I don't know if it's a known problem with the 9K, but there was a service bulletin for the c900 that showed how to correct/avoid the problem. There are clips that hold the weatherstripping to the car. They are covered by a flocked rubber flap that is part of the weatherstripping. The clips have an extra little lip on them that makes them easier to install, but over time they penetrate the rubber flap and scratch the window. The solution is to grind down the extra little lip on the clips. Yours look pretty bad. I'm not sure that you can buff those out, but grinding the rest of the clips down can probably save the rest of the window. That is, of course, if that's the issue--just speculating...