I have a magnaflow(street series) muffler and custom piping and it sounds great cannot even hear it when driving . it only gets loud when you get on it . do not get caught in those names like greddy ,apexi ect. in my opinion you are just paying for the name you will get the same hp gain if any . but the cheaper the muffler the louder it will be magnaflow has different syles if tips and mufflers. and it will cost you less and the couple of hundreds you save you can use it on other performance parts h: