As an aside to my performance tuning questions, what are some good sites for body kits, bumpers, hoods, rims etc etc.

Theres so many out there I dont know which to look at.

 

cervinis

 

The 99-04 GTs already look pretty nice. Just lower it and throw some deep dish Bullitt wheels on it. Also tinting the windows makes a huge difference. I wouldnt go with a body kit on a 99-04 mustang unless its just subtle changes.