My car is a 99 Grand Prix GTP sedan. I have added Energy Suspension Polyurethane Sway Bar and End Link Bushings, A custom K&N cone filter setup and a Thrasher Engineered Performance SuperCharger pulley. Just with these mods I have beaten many of the 5.0 Mustangs in the Saint Louis area, and I have been able to not lose too disgracefully to many of the Formula and Trans Ams in the area.