I have an '88 80 quattro. T.A.P is selling a throttle body for like 300 or 200$.. not sure.. Well anyways, what kind of performance increase would I get out of this and is it worth the money? One more thing, my muffler is really corroded and I need a new one. I know they cost over 200 dollars, is there any alternative performance exhausts that wouldn't cost much more than a stock muffler??