All of the upgrades are cat-back. Basically take the single exhaust at the output of the catalytic convertor, either split it into a dual exhaust, and\or enlarge the exhaust pipe, and the exhaust manufacturers say they also have a less restrictive muffler. I am not sure I would spend around $1k or more for an exhaust that probably doesn't do much other than change the sound, and if I am driving cross country the last thing I want to hear is a constant drone sound.