I have a 01 A6 2.7T with 110000 miles. It runs great but when I turn the steering wheel to the right I get a weird noise! It almost soundslike 2 balloons rubbing together but really loud!! Whenever it rains or I wash my car the noise stops for a while! I tried spraying both side behind the wheel with WD-40 but didn't do anything. I'm thinking it might be from under the car! Any suggestions what it might be?

 

My guess would be a lower control arm binding. When it gets wet theres some slight lubrication that makes it go away. Check for any torn boots on the lower control arms. The uppers too. You may be able to feel the control arms while turning the wheel back and forth and feel virbrations coming from the guilty arm.