When the temperature drops below 35 degrees the windows fog up to the point that you have no visibility. You have to wipe the windows off, only to have them fog back over. No matter where you set the temp., it will help nothing. You have to drive with your window partly rolled down with snow blowing in your face, wiping your window every 5 minutes. Not to mention the hazard of not being able to see and hitting someone! This really needs to be fixed by GM!!