Will try to do more homework on this, but thought I'd throw it out there and see if anyone has any thoughts.

Just returned from extended travel and started up the RS6. Of course, since itís now warm here, I tested the A/C. Was set for 70 in both driverís and front passenger's zones. Blew seemingly cold air to passenger's zone, but clearly warm(er) air to driverís. Eventually, the air for the driverís zone did cool down (some), but was still not blowing at the same temp for the passengerís. So, itís warmer on the driverís side. After driving it for a bit and parking, when I restarted, one was cold and the other was hot. Again cooled down, but not to the same temp.

Itís been a while since I've had an a/c service on it. I assume itís just one a/c system, so I donít know why one side would blow colder than the other. Maybe the driverís zone temperature sensor has gone bad?