I absolutely want to do this retrofit on my new 2012 impreza sport also. I had a few questions.
I can't seem to figure out how you mounted the projector to keep it place. You posted a photo above that shows a threaded end coming out of the hole you enlargened. Is there some sort of cap or nut that threads onto the end of that to mount the projector permanently? Did you have any more photos of how these are mounted?
What are the red and wires coming out of the headlight for?
What type of paint did you use to paint the inside of the housings?
What was your baking procedure to open and seal the headlights properly? I noticed you bought the reselling kit.
Sorry for all the questions. If you can provide whatever photos you took of the retrofit it would be greatly helpful for us to plan out the install before ordering all the parts.