http://www.usmusclemods.com/magnaflow-mustang-exhaust We installed the Magnaflow Mustang Exhaust on our 2005 Mustang GT. There was quite a bit of a tone difference and a little more volume to the exhaust, although not a lot. We haven't done X pipes or anything yet. It's just a cat back kit with race mufflers. It has some really nice looking tips on it, and made a noticeable power difference as well as improved fuel economy. This is one of our favorite Mustang Exhaust Systems out there. http://www.usmusclemods.com/mustang-exhaust