allright dude listen to me, these guys have their ideas, but i also have a 4th gen S (f22). i bought a apexi n1 style muffler, just the end pipe, and not a full catback. i bought this off ebay for about 45 dollars. i was scared that my car wound sound like a ****ing zinger. with that dzzzzzzz noise but no. listen i went to gulf got my back pipe replaced and my flexipipe replaced, this cost me 600 bux, the cat still manufacture made. and my car sound has deep tone. i am very happy with it this sounds very professional and worth the money. my car sounds like it belongs in the fast and the furious. anyway good luck with whatever you decide to do and let us know how it comes out. SOMEONE PLEASE TELL ME WHAT N/A MEANS IM LOST!