Hi, im looking at Jetta's and I want a 2.0 for the gas mileage, but I've heard you can't get alot of power out of them, but all im going to want is a short ram intake and an exhaust system, maybe a chip. What sort of gain can I expect from a cat back, a high flow cat, possibly a header and the short ram intake before a chip? How will it affect HP/Tq and MPG?