Rex, I knew you had a Tom Tom and was wondering how it's worked for ya. I don't see much about them in the reviews, but I think I should start looking at 'em!
Donno, thanks for the warning. Typically I take it out of the vehicle when it's not needed, but as things progress it will be needed more frequently. I know that in the VW it would be 140°F if I kept the windows up on a sunny summer day.