Got a 2003 mustang GT 4.6L 2V with professional products 75mm T.B., dual Flowmasters and a Mac Cold Air Intake. Soon to have 3.73 gears in the rear. I was wondering how some people have these mods and many more while still managing to keep their ponies legal for the streets. Can anyone give me an idea as to how this is done, it would be greatly appreciated.