Did you search? http://www.allfordmustangs.com/forum...s-99-04-a.html
They will fit. Ford has been using the 5x4.5 bolt pattern since forever. The wheels will probably sit really sucked in on the front and back. I used 07 GT wheels on my car, and threw some 1.5" spacers on it, and it looks beautiful. Your front tires will rub on the sway bar, and the k member when the wheel is at lock. It's not a big problem, and only happens when turning left or right at lock, but just be careful and try not to **** the steering wheel all the way over often.
__________________ 99' Rio Red Mustang GT:
Summit O/R H, MAC Flowpaths Turndowns, BBK Shorty Headers, Steeda UDP, K&N FIPK2 intake, Diablosport Delta chip, BBK 75mm throttle body, Trickflow upper plenum, Intake spacer, H&R SS springs, Cross drilled & slotted rotors, "Functional" hood scoop |