When you get into a cold car on a cold morning and press auto in your car, what happens to the air flow? Where does the air come out... all vents? Some vents?
When I press AUTO, I get air from all vents except the central vent. When the car begins to warm up, so does the air... still no air from the central vent. When the car is fully warmed up - both engine and ambient interior temp, the vents stop pumping hot air and pump ambient air. At this point, my central vents suddenly open, and ambient air comes out.
(If, at any time, I press the central vent button the vent opens and air comes out)
I'm sure that's not right. I distinctly remember last Christmas pressing AUTO and aiming the central and driver's side vents at my hands to warm them up!
The thing is... I have a friend with a B7 A4 and his vents work the same way as mine do - no hot air from central vents.
Am I cracking up? I'm sure that no hot air from the central vent isn't right? And if it is, I can't see a sensible reason why those damn Germans would have done it?
So back to the question... what does your car do when you press AUTO?