Ok this is not on an Audi but the response shouldn't matter. I've run my Sirius antenna along the passenger side from my receiver in the front to the rear deck. The problem is that my main power wire runs there as well and I get a lot of alternator whine. The question is what can I do to eliminate it, except for rerouting the antenna wire. Is there some type of insulation wrap that I can use, or anything. Thanks.

did you try unhooking the antenna and see if you still get the whine?