So, this morning, our Q7 began behaving strangely. With the Climate Control set to auto and targeting 20ºC for both the driver and passenger zones, cold air was coming from the passenger vents, but hot was coming from driver's side vents. Adjusting the climate controls to 17ºC or LO resulted in more hot air on the driver's side. Controls appear to work normally on the passenger size and in the rear. Because of the correct behaviour there, I believe the AC system must be properly charged. Are there air dampers or coolant valves dedicated to each zone? How hard is this to diagnose / fix?