Vibration is most definately the motor mounts. Mine vibrated so bad under throttle/going up hills that I couldn't read the HUD. The bad angle of the motor in the cradle caused my right CV axle to go bad. Mechanic couldn't get the CV axle and the steering knuckle apart without ruining the bearing.
Cost a little over 1000 to fix.
99 GTP- K&N FWI,TB Spacer, DHP pcm, Jimmy C "offroad" DP, ZZP radiator, NGK TR55's, Taylor 8mm wires, 3.4" pulley, Gatorback belts, 180* T-stat, Blazer 3200 Fogs, Eclipse stereo/amp, Focal component speakers, Silverstars, 17" ASA wheels, Reflective badge overlays, 35% tint.