The bugeye GD impreza comes with diffuse taillights where (imho,) the reverse lights rarely help for backing up in dark places. There are probably regulations that limit the brightness of reverse bulbs, so an aux reverse lights that turn on only when the gear is in reverse, and when an aux switch is activated is probably a good idea.

Goal:
Brighter reverse lights for my02&03 impreza sedan (GDAA, GDBA, GDAB, GDBB)

Constraints:
(1) Retain/improve functionality of tailight cluster (from legal & safety p.o.v.s)
(2) Retain oem reverse bulbs & make aux reverse switchable but cannot turn on unless the oem is on (i.e. in reverse gear)
(3) Aux reverse is protected from the elements
(4) Integrated mounting of the aux reverse (i.e. no external mount options considered)

This thread may be relevant to you if you:
(1) want to install aux reverse light in a similar manner
(2) have altezza/jaguar style taillight & have issues with leakage (see about 14 posts down)
(3) want to pass wiring from the engine compartment, through the side sills, to the trunk (see about 24 posts down)
(4) just want to browse around :)

The following 28 posts or so summarize my DIY that lead to the taillight cluster shown in the picture below. Photo shows a modified clear-lens taillight (aka Altezza style) where the original reverse light (lighted in this picture) has been relocated to the bottom of the turn signal.

http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev001.jpg

Photo below shows the original taillight in which this DIY starts from. The main point is to have clear lens cover in the area where the aux reverse lights will be mounted on, and where the original reverse bulb will be relocated to. Clear lens will minimize light attenuation that is prevalent in the oem taillights for example. A secondary point is that with the clear lens, the assembly must have adequate reflector design to spread the light.

Altezza light was chosen here because it is less expensive than an oem my04-05 taillight replacement, especially since this particular pair was bought used.

A preliminary set of observations was posted in the following thread:
--> http://forums.nasioc.com/forums/showthread.php?t=543930
where I examined the passive reflector & intensity of light of the various components of the altezza compared to the oem taillights. Imho, given the advantages and the manageable shortcoming, the altezza taillight was a suitable starting point.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/compare00.jpg

Step 1: Remove the clean lens from the taillight assembly by the standard bake&pry method. --> pre heat oven @ ~250 degrees, turn off, insert one taillight at a time for 10-15 minutes, remove & pry open slowly.
Step 2: Repair paint (the altezza had prior leak issue, adressed later in this thread)
Step 3: Test functionality of altezza style taillights. See the link in the post above for the details.

Picture below shows where the original turn signal and reverse light sockets are, and the 35W aux reverse light unit to be integrated into the taillight assembly. Original reverse signal is 21W iirc.

A clean way to cut the socket is to use a hole cutter. Problem: need a pilot hole for a good, concentric cut. This is because the socket will be used to relocate the original reverse bulbs later.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev002.jpg

Photo below shows a hole cutter whose ID is slightly smaller than the diameter of the opening.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev003.jpg
Using this cutter, drill a rigid piece of material. I used 1/8" thick acrylic panel as shown below. The resulting hub is circled in red.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev004.jpg

Mount the custom made hub as shown in the picture below. Adjust fitment with tape if necessary.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev005.jpg
Mask & secure the hub using tape (so it stays in place during cutting).
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev006.jpg
Cut reverse socket from the rear/inner side of the taillight cluster. This is because the outer side has uneven reflector facets that can make clean initial cutting tricky. This time, choose a hole cutter whose OD is slightly smaller than the diameter of the aux light.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev007.jpg

Use drum sander to smooth out the edges.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev008.jpg

Check the clearance for the aux reverse light unit. Picture below shows the recently cut hole, indicating that there is a bit of sheet metal (yellow with green dotted line) that needs to be taken account of when chosing the aux light unit. Blue circle indicates approximate size of the original reverse socket & bulb set.

Also note the somewhat unsightly turn signal socket & bulb showing. This will be dealt with later.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev009.jpg

Picture below shows the inner side fitment. Aux reverse light barely fits in. This eliminates the possibility of larger & more powerful aux light units such as the PIAA 959 turbojector.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev010.jpg

Mount the reverse light using a simple 2-bend bracket as shown. The Simpsons Strong-Tie brackets (can be found in Home Depot) seem rigid yet workable enough for this job. The original piece is marked #1. #2 is the original reverse socket that was removed. #3 is the metal shear that was required to do the bracket trimming. #4 shows an assortment of nut, bolt & washer.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev011.jpg
Since the hole must be made slightly larger than the aux reverse light, some flexible material should be wedged between the hole on the taillight cluster and the aux light. Picture below shows a neoprene-like insulation tape that has the right compliance & thickness. This can be found in Home Depot. As shown in the picture below, cut a small strip and tape in around the aux light. Do not overlap.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev012.jpg
Even though the insulation tape has the right compliance & thickness for interference fitting, the square edge makes installation difficult. I used 3M electrical tape on the edge of the insulation tape to round off the edge for easier insertion. The goal is to have a snug but easily removable fitment for bulb replacement.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev013.jpg
Picture below shows the aux lights mounted on the tailight clusters.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev014.jpg

The altezza style taillight has 1 rearward facing reflector and 1 side reflector on each unit. Per my observations posted in http://forums.nasioc.com/forums/showthread.php?t=543930
the rearward facing reflector (round in the picture below) has a slightly smaller surface area compared to that of the oems.

To make up for it, an additional retroreflector strip is added as shown. Retroreflectors can be purchased in many hardware stores, although imho, 3M's Scotchlite is preferred.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev015.jpg

When everything is completed to satisfaction, re-seal the taillights.
Warning: I re-sealed the lens to the taillight assembly only to change my mind later on and added the further modifications shown in the following posts. This made things more complicated. Resist the urge to seal the taillights unless you're absolutely sure no more changes need to be made :p
Opening the taillights the first time was a pain; re-opening them again may not be as easy depending on your choice of adhesives.

With that in mind, the photo below shows the taillights re-sealed. I tested 3 adhesives shown:
(1) "Household Goop" --> most viscous of the 3. Clear and compliant when dry. Most suitable to replace the original caulk-like seal imho.
(2) "Silicone II Household Glue" by GE --> less viscous than #1. Good for filling imperfections left by #1. Clear but a bit less compliant when dry.
(3) "E6000" adhesive. Very strong. Comes in choice of black & clear. The tube was very hard to work with (started leaking after several presses). Otherwise, a good adhesive.

Warning: when re-sealing, cover the clear lens with a good masking tape. It is very easy for the adhesive to find its way to the lens through fingers and nearby objects. Remove only after the adhesive has dried off.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev016.jpg

After re-sealing, paint the edges to hide the imperfections. Use masking tape to create any paint schemes desired. I used:
(1) primer for a good paint adhesion
(2) high-temp metallic silver paint for the base of the red portions
(3) "anodized red" for the red hue on the red portions. (the paint itself is semi translucent, hence the silver paint is necessary)
(4) clear overcoat to coat the final paint, but not the unpainted area of the clear lens.
(5) black (with metallic flakes) paint to cover the glued areas
(6) frosted glass effect to further mask the surface imperfections of the glued areas
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev017.jpg
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev018.jpg

Photo below shows that both the oem and altezza-style taillights have a bit of a gap running on top where water from the trunk's side gutter can run into. In the oem taillight, there is an "inner wall" that seals the actual opening of the sheet metal to prevent water from entering the trunk & inner taillight area. However, the outer flap shown does not make a proper seal.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev019.jpg
Since my altezzas didn't come with seals around the inner wall, I used the same insulation tape shown in post #9 around the inner wall as shown below. I'm not sure whether altezza units bought new comes with a seal or not.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev020.jpg
As it is, the unmodified altezza (unmodified in the sense of the seal) has a leakage problem as others have reported. This is not surprising given the fact that one of the columns used to hold the mounting screws protrude farther than the inner wall as shown below. A simplified side-view drawing is shown in the picture below.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev021.jpg

To test for leaks, water was sprayed on to the taillights using various methods, including:
(1) spraying directly onto the clear lens from various angles
(2) spraying onto the gap between the taillight and the fender/trunk/bumper
(3) simulated rain : roof & windshield --> trunk drainage system
Photo below shows test#3, which imho is the most relevant test for leakage.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev022.jpg
Not surprisingly, there is evidence of leakage. A small pool of water is shown accumulating on the bottom of the inner brake light unit. I bought this used altezza with similar evidence of leakage in the same area.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev023.jpg
Picture below shows the inner side after the rain test. Blue arrows show where water would've travelled on the outside, and then entering the trunk area through the opening caused by that protruding column shown in post # 13 above. This area is circled red (on the right hand side of the picture). A secondary but smaller accumulation of water can also be found on the other end of the taillight (also circled red). This is probably because the protruding column causes the entire top side of the inner wall to not mount securely to the sheet metal. To make matters worse, the secondary area is where most of the rain water pours down to from the trunk gutter. But because the protruding column is on the other side, it doesn't get as much water.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev024.jpg
Photo below illustrates the qualitative flow of rain water from the trunk gutter. The blue arrows show water flowing on the visible surfaces. As water travels down from the trunk gutter, a lot gets accumulated on the blue circled area, which then enters into the gap between the taillight and the sheet metal. The inner wall provides the necessary seal, hence water flows down in the manner shown by the green arrows. The protrusion (circled red) renders the seal between the inner wall and the sheet metal ineffective.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev025.jpg

A simple solution is to trim off the protruding column. Even if the mounting bolt becomes unusable, this is clearly better than an open gap.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev026.jpg
Similar leakage test confirmed that this solved the problem.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev027.jpg

For extra insurance, eliminate/reduce the amount of water from the trunk gutter flowing on top of the inner wall. Use any flexible and water tight seal such as the pipe insulation used in post #9 & 13 to close the gap between the upper portion of the taillight and the sheet metal. The picture below shows the seal dotted in yellow.

Note: this seal does not disrupt the flow of water from the trunk gutter to the ground.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev028.jpg

After the aux reverse light is mounted, I decided that the oem reverse light should be retained along with the oem wiring. Picture below shows the cut reverse light socket placed just under the turn signal socket. Given the reflector design, this location provides minimal change in turn signal funcitonality imho.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev029.jpg
Mark the center, and generate a grid, taking into account the fact that the surface is curved. The grid is useful because you will be making an oblique cut such that the rotational axis of the bulb socket points straight to the back of the car.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev030.jpg
Since this mod was done after I re-sealed the clear lens, mask any opening before cutting.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev031.jpg
Also, to minimize the spreading of particles inside the now sealed taillight housing, cutting the hole must be done with the hole cutter pointing upwards as shown. Place a secondary support next to the cutter so that when the hole is completely cut, the taillight doesn't accidentaly drop down. Otherwise, the inner surface of the clear lens could get damaged by the pilot drill or the hole cutter.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev032.jpg

Picture below shows the hole partially cut. The green oval indicates where the secondary column is.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev033.jpg
Smooth out the edges.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev034.jpg

To mount the original reverse light bulbs, use the cut off socket and fabricate some mounting assembly for the socket. One simple way is to use acrylic tubes and cabochons, which can be purchased at your local www.tapplastics.com store. Acrylic is preferred over polycarbonate/lexan/tuffak in this case because, imho:
(1) higher temp sustainability is not important for low power (i.e. low heat) reverse lights that do not turn on for long periods of time
(2) while slightly more brittle than polycarbonate, it does not make it too difficult to machine
(3) shaped acrylic is less expensive and easier to find than polycarbonate
(4) acrylic has better optical clarity compared to polycarbonate, and has better UV resistance to yellowing than regular polycarbonate. Treated polycarbonate is also resistant to yellowing, but even more expensive

One possible configuration is shown below:
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev035.jpg
This is approximately how it will look when installed. As previously mentioned, the turn signal is rather unsightly since the clear lens exposes the socket. A smaller set of tubes & cabochons can be devised to cover the turn signal.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev036.jpg

The simplest & easily removable fixture I came up with at the time was using a few screws to pin down the fixture from all 6DOF of movement. The picture below shows 4 self-taping screws (purple circles) drilled onto the sides of the fixture. As it is, the fixture can rotate along the red dash-dotted axis and fall off.

The arrows provide a simplified illustration of the reaction forces (in cartesian coordinate system) on the 5 points against the fixture. Strictly speaking, the oval wall of the cut hole also provides reaction force, but does not change the fact that the 4 screws do not provide complete 6DOF constraint on the fixture.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev037.jpg
A final screw position as shown below provides the proper constraint. Removal of the fixture (when necessary) is done by simply removing this screw.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev038.jpg

Since the turn signal bulb mounts on the original socket, a different mounting scheme needs to be used for the acrylic tube & cabochon. I fabricated a bracket out of thin aluminum sheet metal in the manner shown below. There is a long tab that will go through the back of the taillight housing and 2 short tabs that press on the hole.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev039.jpg
The bracket mounts to the tube in the manner shown in the picture below. A single screw is enough to secure the bracket to the tube (not shown).
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev040.jpg
Picture below shows a test fitment of the tube+bracket on the taillight cluster. Note the 2 holes for the aux & original reverse lights.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev041.jpg
To mount the bracket to the tube, a single #4 wood screw is sufficient.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev042.jpg
Side note: cut-resistant Kevlar work gloves are indispensable for DIYs. They're breathable and provide surprisingly high amount of tactile feedback (compared to thick working gloves), yet provide good heat & cut resistance. :)

The rear of the socket should be filed off as shown for the tab to pass through and maintain proper seal.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev043.jpg

The cabochons will be secured to the tube using adhesives. Since they are both transparent, it is a good idea to obscure the contact area. One way to do so without attenuating much light is to use a frosted glass paint. Light will still shine through, but the unsightly glue will not show as much.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev044.jpg
Next is light management. For the original reverse bulbs, I wanted to direct more light through the cabochons. The half sphere shape of the cabochons make a properly placed light source refracted & focused to an almost parallel beam. Since the aux reverse light provides most of the spread pattern, I wanted to reflect as much light from the original reverse bulb towards the cabochons. An easy way is to use the chrome coating decal shown below. I used silicone adhesive to secure the cabochons to the tubes.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev045.jpg
Picture below shows a closeup of the aux reverse light and turn signal covers. The aux reverse light units have chrome reflectors installed. Chrome reflectors are not installed on the turn signal covers since I wanted to retain the turn signal reflector in the altezza taillight units. Use a thin, flexible tape such as electrical tape to provide snug fitment of the cabochons into the tubes. Also, it is a good idea to label which units are for the left & right hand side.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev046.jpg

Install the fixtures/covers. Use oem wiring & bulbs.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev047.jpg
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev048.jpg
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev049.jpg

The aux reverse is wired such that it will turn on when both:
(1) the reverse gear is selected
and
(2) the aux reverse switch is turned on

The light unit chosen comes with a standard harness consisting of wiring to the light units, a relay, a fuse, and a switch. The (+) & (-) leads of the switch (yellow circle) connects to the brown & black wire of the taillight cluster (reverse signal). The (+) & ground leads from the relay (blue and green circles) connect to the battery.

If you want a completely independent aux reverse lighting (which may not be legal in some areas), connect the wires circled in yellow with either a switched or unswitched power supply.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev050.jpg

I decided to run a power line with a separate fuse from the battery to the trunk area. Afaik, the wagon imprezas come wired with a 15A power line leading to the aux. 12V accessory socket in the back, while the sedans do not.

One way of running wires from the front to back is through the side sills, under the rear seats, and through the panel that separates the cabin & trunk (behind the rear seats). First, remove the clip on the front row side sill. It is a 2-piece clip, which can be removed when the head is completely pulled off.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev051.jpg
Next is a screw-like clip near the dead pedal. Use a flathead screwdriver. Iirc, a quarter turn should do it.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev052.jpg
The front side sills can the be removed by pulling it upwards. There are 4 clips on the bottom.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev053.jpg
Next is the rear seat. Remove the 2 screws that secure the bottom of the rear seat. Use a 12mm socket. Remove the bottom of the rear seat.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev054.jpg
Next, remove the clip on the B-pillar. This can be accessed from the rear seat compartment facing the back of the front seats. Pry with a round-edged flathead screwdriver. It comes in 2 pieces like the first clip above.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev055.jpg
After removing the bottom rear seat, another clip can be seen. The clip has ribs that provide interference fitting. Simply pry up with a flathead screwdriver.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev056.jpg
Afterwards, the rear side sills can be removed in the same manner as the fronts. Note similar clips. Only 2 of them instead of 4.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev057.jpg
The b-pillar lower cover can then be removed simply by gently prying it off the sheet metal. Work your way from the bottom.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev058.jpg

Remove the 4 screws that secure the backrest of the rear seat. The screws are on the bottom of the backrest. Unlatch the trunk passage door / armrest by pulling it. Slide the entire backrest upwards to free the 4 hooks on the top side of the backrest.

With the backrest removed, remove 2 clips from the cabin (yellow), & 1 from the trunk (green).
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev059.jpg
The liner can now be pulled away as shown (green arrows). There's another clip (red). This secures the sidewall of the trunk liner.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev060.jpg
Now wiring can be passed along the sidewall of the trunk liner (dashed green line).
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev061.jpg
Picture below shows the fused power line I ran from the engine compartment into the trunk. New accessories can tap onto this line by adding jumpers and making sure the fuse is of the correct rating.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev062.jpg

A commonly used firewall passage is shown here. It is easier to pull the grommet entirely, cut a hole, push the wire through, push the wire through the insulation material over the firewall, pull the wire from the cabin, and then push the grommet back in place. If you have a strut tower bar and happen to have an intercooler, one of them must be temporarily removed.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev063.jpg

Picture below shows a comparison between unmodified altezza turn signal (using oem bulbs) vs oem turn signal.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev064.jpg
The next one shows a comparison between modifed altezza turn signal (with the acrylic housing) vs oem. While the conditions when both pictures are taken are not the same, comparison with oem on both cases show that the addition of the original reverse light housing in the turn signal reflector area does not noticeably reduce the brightness of the turn signal from this angle.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev065.jpg
Picture below shows an alternate view of the latter.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev066.jpg

Last step.
Picture below shows (top to bottom):
(1) oem vs unmodified altezza reverse
(2) modified altezza reverse, original bulbs only
(3) modified altezza reverse, both original & aux
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev067.jpg

Wow, that looked like a very complicated mods you've done, but the result is almost like the MY04-05 style, with a better round brake light imho.
To me you're still the reigning King of DIY. Well done :banana:

Thanks for your feedback. :)

Daytime photos. Unsightly base for the orange turn signal is not visible. The orange bulb color only shows when lit and from certain angles when unlit. The original reverse signal is hardly visible when unlit as well.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev069.jpg

Hey. .. Although the look of this mod is somewhat odd, I do recognize the ingenuity and effort that took place in your project. This was very technical, and well done indeed. Do the convex lenses focus the light too much? They almost look like mini headlights :)

Thanks for your feedback.
Do the convex lenses focus the light too much? They almost look like mini headlights :)
The cabochons (those half spheres) do act like a convex lense. On the turn signal, the difference is like illustrated in the picture below. Note that the reflector's curvature in the illustration is not correct. However, the beam path looks as illustrated.

The original reverse bulbs also gets focused to a near-parallel beam. This is fine in my case because the aux reverse unit added provides a brighter and wider spread.
http://mechatro2.me.berkeley.edu/~satrya/pics/photos/imputaillight/rev071.jpg

Wow!!! What a write-up! Thank you for your time and effort for sharing with the community!

Thank you for your time and effort for sharing with the community!
Thanks for your feedback.
Since you have a my2004, the reverse bulbs are probably better than the ones in the my2002-2003. So this DIY is probably not so relevant :)

But I suppose you could do something similar for a reverse / night vision camera mount.

... thumbs up for blaze yellow.. :)

... thumbs up for blaze yellow.. :)
Thank you, fellow 797 :)

All Hail The King Of DIY Mods!! http://www.socal3g.com/forums/images/smilies/bowdown.gif

damn dude that was awesome. way too complicated for my simple hands and tools. :(

it would be cool to see some output pics :)

again, great work :D

RR :D

That's a funny gif :)
it would be cool to see some output pics
You're right. I haven't taken any images of the projected beam. If I feel motivated, I'll put the original taillight on one side and compare it with the modified one.

Thanks for your feedback.