The Tubi is all I tweaked on the engine side. The exhaust is not for everyone. At low rpm's there is a boominess in the cabin, but at rpms over 2.5-3k there is no issue at all. In the higher rev range, the car truly shrieks. I blew by a guy in an S2000 yesterday and I could swear the look on his face was pure bewilderment when I saw him at the next stoplight. He had no idea a Boxster could make such nice sounds. If you are looker for a more aggressive sound I would recommend it to anyone.