I have a 2010 G37s M6 sedan and I'm looking for a good aftermarket exhaust system with good HP gains over stock but not one that is really loud (unless i floor it i guess LoL) any one have some advice for me? Thanks

 

It is tricky to recommend something, because people's taste is soooo different. I have Tanabe exhaust on 03, which is whisper quiet while cruising, but gives a nice bark when I floor it. Tanabe bills itself as maker of "quiet" performance exhaust.
Many people have complimented me on sound from outside.
Go to photobucket.com and do search for my user name-I have quite a few clips there.

 

Check out tanabe exhaust.. They're good for what you're asking. They're quiet and gives that good growl...

http://www.tanabe-usa.com/touringmedalion.asp?id=7