Here is some info and details of my install of a Rydeen MINy camera using SVXdc's 16 pin harness with the stock 6 volt wire out of the Fujitsu FW602US nav unit in my '12 WRX hatch.
I confirmed with tech support at Rydeen that the camera has an operating range from 3.5 to 15 volts. I suspect other cameras both from Rydeen or other MFGs will work the same way, but I recommend checking with their tech support first.
The nice thing about this setup is, the camera doesn't need to be constant powered and there is no splicing into other wires necessary. It also seems that the head unit turns the camera on correctly at boot up. The MINy has switchable guide lines.
The camera I got is the MINy, 1st one, top left of the page
I ordered from one of their authorized distributors for warranty etc., they were within $1US of the cheapest shipped price on eBay when I checked.
The harness and plug came from here.
Make sure you tell Dave, you want the stock power out option if you are going to try this.
I was working alone and so I didn't document the cable routing, particularly because it is done many times elsewhere in this forum. I can tell you a few things and I do have a couple of pictures of things I did differently.
I needed to extend the camera power lead so it was long enough to run to the head unit, since I'm powering off the factory 6 volt out using SVXdc's harness with the extra factory power pin out. I made all of my connections with solder and shrink wrap.
I have not tested this but apparently it's not necessary to extend the power cable to the back of the HU, there's a little pigtail that says something like "backing power supply anode output" that comes out of the side of the video RCA which can be used to power the camera.
Please test before you attempt to use this for power.
I chose not to drill any holes so I popped off the hatch panels, removed the Driver side license plate light housing and ran the cable through there.
Here's what it looks like put together. It's held on with earthquake putty until I can get someone over to help me aim it and then attach it.
I ran the wires along the Driver's side of the car.
I used this tool made out of a piece of wire hanger
to get the wires through here
Note camera ground location
I pulled off this entire panel
once it was off I was able to route the cable through here following the existing run, after that I just pulled the sill panels off and tucked it in there. To get past the B pillar I used an electrician's fish tape and then gently coaxed it through.
I ran the cables up through the rocker panel and tie wrapped to cables under the dash. then found a path through to the back to the radio.
With the radio pulled out I soldered SVXdc's power wire to the extended camera's power wire. Plugged in the new connector and then tested.
Go into reverse, camera goes on, go out of reverse, camera goes off and the radio, nav etc. works like normal.