My son and I are going nuts. It seems right after getting exhaust work done, there is a loud annoying "humm" when the car is turned off and the radio is on. We don't know why the radio works when the car is off, must be an Audi thing. When you start the car, the noise is still there, and the frequency goes up and down with the RPM but the volume of the noise never changes. If you turn up the stereo loud, you can almost mask it. We have checked grounds, disconnect the antennae (which seems to make it decrease in volume a little). It is a Bose Concert 2 with amp and 6 disk CD changer.

We think the welding on the car exhaust blew up the noise filter on the radio because the unit was "on" yet the key was off. It may be a coincidence but it happened right after we got the car back from the shop.

We would like to swap out the radio and here is our question. Anyone have one they want to borrow to us for some good Audi karma? We would install it, check for the hum and then send it back to you. We would buy it from you if it fixes the problem if you want to part with it. Anyone wanna help out? This issue is driving us nuts. We would trade you an aftermarket 2 into 1 Magnaflow CAT that has been used 2 weeks if you want to trade something. We decided to update the down pipe after we did the CAT back exhaust and then had to go 1 into 1 CAT 2 weeks later

 

Anyone have a radio they want to let us try? Have you heard of this problem? Have you ever driven a car without a radio? It sucks!

 

Bumparooni