I've got an aftermarket Exhaust System for sale made to fit an 02+ WRX. It's an RS*R GTII Catback System still in the box, unopened direct from RS*R USA. This is the straightest piping route you can find for your car. RS*R is not as popular as some other traditional aftermarket exhaust systems (GReddy, HKS, etc.), but performance and soundwise right up there with, if not better than the competition.

Somehow ended up with two of these in my possession, one of which I recently had installed on my '05 WRX. Power gains were noticeable and sounds amazing. Take off the silencer and this thing's LOUD.

This system's impossible to find brand new like this for under 550 shipped anywhere. Looking to sell mine for low 400's (shipped). If you're interested and have a reasonable offer, and need any more info (pics, sound clips, etc.), PM me. I'll give you me e-mail and AIM screenname if needed.