I have an 02 2.0L Jetta and i was wanting to upgrade my exhaust. I was just wondering how exactly i would do that? Like i would want a 2.5 or 2.25" pipe and a new 2.5" down pipe b/c i heard that is where most or your horsepower restriction would be. Also i would like a new header for this system. I just mainly want to know about how much it would cost and where i could find these parts for a 2.0L Mk IV Jetta?