Just thought I'd add some info for those worried about water damaging your speakers which was covered earlier in the thread. I have 04 STI. I washed my car the other day with the door panels off and was able to see that a decent amount of water entered the door. I understand that this is not comparable to a rain because of the direction and pressure of the water spray, but we I wash my car a lot and wanted to see how this scenario was. What I saw was almost like a spray on the outer door skin right behind the where there speaker would go. It's hard to say what the culprit was for the water entering the door but here is my observation:
I didn't seem to see evidence that the water leaked down from the window seal or dropped from above based on the way the water was sprinkled on the door panel. Now, when I looked at the "gutter" in between the car and door where the stock wire looms runs, there is a ton of water that flys around in there. Granted it is designed to do this, I felt like if I could find an entry point there it would be a good starting point to help keep water out proactively. Firstly, has anyone tried plugging the small hole under the grommet of the stock wire loom on the door side of the loom. There is a small hole there about the size of one of the door panels clip holes. You can easily feel around for it or you can see it from the inside of the door if you haven't sealed it up too well. There was water all over this area and was coming in there easily. I put some silicone and tape to plug the hole. The only reason I can think this hole is there is to allow moisture to exit the door. I haven't washed again to see if this helped at all but will post some results if anyone wants to know.
Anyway, the reactive measure I took was to make a shield around the speaker with an XTC foam baffle but make a cutout on the bottom to allow air flow. If you view the baffle as a 360 degree circle. I probably cut out 90 degrees on the bottom so I could still get good water protection and left the back completely on. I am skeptical about how this is going to sound. But I am still working on my amp rack and haven't determined if the baffles are impeding the speakers too much.
On a side note, I installed the CDT CL-62s which are pretty deep speakers at 2.88 inch. So, the baffle messes up the clearance I obtained from the IAP spacers and grinding down that window guide piece. I did shorten the baffle a bit too and actually glued it to the speaker housing ( it's not going anywhere like this), but it's thick foam and there is still friction between the baffle and window piece. I may end up just not lowering the window that extra couple of inches so I can keep my rain guard there. This is my first car install and there is probably a better way but....