I've seen that mark on so many windshields and just never paid it any mind. That's neat to know, and helpful, too! When I had mine tinted I asked the shop about the shade and they said they wouldn't trim it to follow the top of the windshield contour, but instead it would be a straight edge that would appear to droop at the sides. I didn't want that for my car so I decided to save $25. How hard was it to get it to look right? Got any pics? Please?