I had nothing behind the mufflers, sounded great but too much exhaust in the car. I put tailpipes on, sounded gay but didnt get much exhaust smell. So I went to dumps, sounds almost as good as nothing behind the mufflers and it still smells pretty bad in the car with the windows down. I have an offroad H pipe. So I guess you need to base your decision on how much sound you want to sacrifice to not pass out in the car, LOL.