I have a '01 E320 that the stereo volume increases when turning left at very slow, parking lot type speeds. It only happens occasionally and does so while playing the tuner or tape. The volume goes up so dramatically that I have to turn it down. I know that it is not the volume rising slightly from an increase of vehicle speed nor am I inadvertently pushing the volume increase on the steering wheel.

Any suggestions?

Thank you.

Sounds like compooter problems to me.
take it to the dealership.