Okay.. I give up.. My '95 A6Q runs like atop... but when I turn on the AC, with the twin fans come on and create a low rumbling hum *inside* the cabin. Sounds just fine when I get out and listen to the car... the fans appear to be running just as they should. Question: is something loose that is causing this humming inside the car? Anybody have a similar experience and/or fix?

Vielen Herzlichen Dank!