One of the biggest things that the 1999 to 2004 Mustang GTs lacked from the factory was a big, booming exhaust roar, not to mention the extra power that comes from an exhaust system that's actually efficient. For whatever reason, Ford just didn't put a lot of effort into making your Mustang GT's 2V 4.6L V8 sing, but the vast Mustang performance parts aftermarket is here to help. If you're looking for a bigger, booming exhaust note, then start off with our cat-back exhausts. If you want power, then move on to a set of headers and a performance mid-pipe.