Yupers I concure with mr. zone above. I'm currently running an '07 sti downpipe mated to an '04 sti resinator/axleback on my '02 wrx. Fit perfectly.
Why in the hell would you want to replace one crappy downpipe with another crappy one?!? lol! The only part that would be an upgrade over the WRX is the axelback.
It's a very cheap option for a little bit better downpipe. Or, maybe he needs to replace it on the cheap. Who knows, it's just a question.
I can understand if you need to go back to stock or something like that, but to do it as an "upgrade" is just a waste of $$$.