I have a 2008 Edge that I purchased new that still has only 26K miles on it. I have used the rear window defroster a couple of times when it was damp and mild outside and I noticed that it doesn't work well at all. It barely clears the glass at each line heating element but not enough for the cleared spaces to merge leaving clear glass. Can't imagine how poorly it would do in a really cold and icy invironment. Does anyone else have this problem?