great list man, I would like to help add some stuff such as sterring wheel selection and to add/change the seating, wrx changed its seats for the 04-09 models, they look just like the sti ones but they are all black same direct bolt on like all the other subaru seats. I will have these installed next week and I can take a picture for you.
Can you make a Steering wheel section as people would might like to upgrade to wrx steering wheels or sti steering wheels or even the jdm steering wheel if u can find the clock spring for it.