I just bought a 1990 V8 and What a car! Of course, right after I bought it and a day later I hear this hissing whenever I go over a small bump. I pushed down on all four corners to see if it is coming from the shocks and it is not. It is driving me crazy. Any help/hints is appreciated. P.S. I am new to this Audi world. Is there a place you guys/gals recommend where I can buy computer chip to replace the stock?