Purchased 850 six weeks ago. Have had a few minor problems that the brickboard message archives have helped solve - the dealer is most impressed, even intimidated, with my sudden depth of knowledge on 850s. However, he is having the last laugh. Every morning I awake to a layer of condensation on the car except on that part of the windscreen that contained the dealer's signwriting. "one owner, low miles, great value, etc". I have tried every household chemical and even a razor blade. Is there a tint in the screen that has been affected in some way?