Anybody know what the white crud is that comes out from behind the side view mirror mount (that triangular shaped thing on the door) when you wash the car. If you leave the hose water there, it never seems to stop coming out. I have seen other Golfs with water stains on the door just below the side view mirrors. Any hints on how to get rid of the white crud and stains on the door. Washing with car wash soap doesn't do it.