Strange A/C Issue

[Tset]

I have a 2001 A6 4.2 and I'm having an issue with the A/C. The passenger's vent blows cold the passenger side center vent blows cold, but the driver's side center vent blows warm and the driver's vent blows almost hot air. It's as it gets warmer from right to left.

I thought the air came from the same place. Any ideas? It's not much fun sweating while driving and the passenger is too cold.