Originally Posted by alofoque
The vibration came early december when i still had my AA Race Xpipe. The AA was installed within first month of ownership (August2012).
I'd track down and throw an entirely stock x-pipe on to see if you still have the issue.
Drastic measure maybe, and you'll have to take an afternoon and pay for some lift time, but since you're about ready to get rid of the car because of the issue..