X2 Completely agree.Yup, what Moss said. As far as exhaust, the stocker is hard to beat performance wise, but I don't know what you are trying to do. I run and UMP air filter and love it, but Dragonfire Racing has a good one too. Some people build their own, etc. Search the threads for discussions on all the questions you ask, you'll find more information than you wnat to know.