I just got an 05 mustang gt what is a good first performance part i should get for a diesent price?
Depends on your definition of "decent". Start with some bolt-ons first.
-Cold air intake (roughly 8hp gain or so and looks good)
-BBK shorty headers and Flowmaster mufflers (roughly 20-25hp gain and great sound!)
-Lower rear end gears, ex. 373's (no hp gain but significantly quicker acceleration for a decent price)
-Short throw shifter (quicker shifts = faster acceleration)
Hope that helps!