I have a 2006 Passat and everytime I drive it the windows fog up, any solution. I went to my local vw dealer and they have not heard of that happening before. But there solution was put rain x on the inside of the windows. I did of course and it srcewed up the windows. I think I will try vinger to remove it.

I had this problem too. this is very annoying, and also a safety hazard. After a lot of investigation, and a few trips to the dealer, the cause was determined to be a non-functioning recirc door. recirc door was stuck on, and humid air from the cars interior (wet shoes, breathing, etc.) was being passed directly onto the windows by the defrost system. Dealer closed the door, and it went away immediately. Recirc servo motor part was ordered, and replaced. good as new. was covered under pre-owned warranty. Hope this helps anyone else.

I have the same problem. It only happens when its raining, cold or when its snowing outside. It takes about 20 min for the entire fog to be completely out of my windshield. The backwindows stay fogged the entire time even after the heater is working full blast.. I'm going to take it to the dealer ship too and see what they say.

When driving the car in cold weather, the A/C compressor should come on when the defrost is on. And, when the car is driven a short distance, enough to heat the engine coolant, and it is cold outside, on restart of the engine, moisture or fog will temporarily cover the windshield. How long depends on how hot the coolant got, and how hot you have the heater turned on. There is a thermodynamic process happening here that is not easy to understand.

Your A/C compressor must be operating though in order for this dynamic to occur.