Especially on my rear window, a foggy residue often appears. The defroster doesn't help at all and it cleans away nicely with windex but comes back in about a week. Does anyone else have this problem? It happens in the front as well. Are there any products i can treat the windows with to reduce this? It is just annoying to have to clean all the time.

 

The Gemans have a name for it - bung something-or-other. (translated: ****) It's caused by plastics in your interior gassing, and usually is worst in hot weather. I have seen a few products that claim to clean it off better than traditional cleaners. About the only way to avoid it is to crack your windows a little when it is sitting in the sun to let the gas escape. Although this is always an invitation for the bad guys to screw with your car!