Strange marks on door
Hi... I have a 2009 26BH and as of the last month I've noticed strange gray marks on the door (only the door). It looks as though it's crackled, but it's not into the paint. I tried everything to clean it off but nothing seems to remove it. It also seems to be increasing in the area of the door. Does anyone have any idea what it could be? How to remove it or prevent it from getting worse?