I'm looking to firm up my ride a little, especially in the sharp turns, and I'm having a hard time finding the needed parts, or any "performance" parts for the Bonneville. So the question is, how similar are the GP'* to the Bonneville'*? A good example is a CAI...3800 performance lists 3 or 4 of the for a 2000 GTP but not a one for a 2000 SSEi...any reason why it wouldn't work?

Drivetrain is identical (or very nearly so). Suspension is totally different, as are the underhood dimensions. Any CAI will have to be modified, but it'* not difficult.