Well, some did come with upgraded alternators and tranny/oil coolers, and some did come with roll cages which can be a nice addition if you're going racing anyways. The only downfall is that you know the cars have been driven and driven hard (unless you're fortunate enough to find an Airforce/FBI Mustang, but those are RARE) but as the saying goes, cars that are driven hard from day one are usually the fastest.