Speaker mounts I made for my 2005 WRX Wagon.
These should work for other Impreza/WRX models from around that vintage, you probably won't know for sure until you get the door card off.
Tip - don't remove the screw for the door handle. Only the plastic trim around the handle mount needs to come off and it's annoying to get the latch connection rod reseated.
The screw holes are slightly off on the fronts because I was in a rush, but not enough that it matters (never take your car apart at 10 pm if you have to work the next day). Rears are precise though.x
Fronts:
5 ¼"
I'm running the Infinity Reference REF-5030cx component set. You don't need anything special for the tweeters IIRC.
Rears:
4"
I'm running the Kicker 46CSC44 CS Series 4" 2-way speakers.
The author marked this model as their own original creation.