Your "choose a model" did not work. I own a Hyundai Terracan Sept 2003 reg. When the climate control is set to heat the car during cold weather all the windows, not just the windscreen, get fogged up. This remains on the glass until it is cleaned off which is very difficult to remove so it is not just condensation. In bright sunlight something similar to heat haze is visible through the vents. I had a new cabin filter fitted but this has not solved the problem. After about 45 minutes of driving I have to stop to clean the windscreen. Any ideas as to the problem and a solution?