Thanks. How tough is the tranny? Ive got the $$ and im in no rush because my wife and i have 3 other vehicles. I also have two other friends who know quite a bit about subarus. Its just merging the harness and the wrx or sti trans install that my question was about. The op only listed 02-05 wrx wireing diagrams.The only thing limiting you is time and budget. To answer your question, yes, you can swap your car to an 07 STI engine.