I just recently purchased a 2004 A4 1.8T. I plan to add a chip, probably upsolute(anybody have any experience with this brand?), air filter, and exhaust. The problem is that all the systems I have foud are around a $1000. I am looking for a cheaper way to open it up. Does anybody have any ideas about just replacing mufflers, what kind, and will s4 mufflers fit? Where can I get this stuff?