: I was backing out slowly in a crowded parking garage (they had cars parked in the access lanes). I stopped momentarily because I saw another car waiting to get by. The pressure of another car waiting and the fact I am not yet proficient with the manual transmission of the BMW, I backed up some more for extra leeway to manuever, but I didn't look. As I slowly backed up I hear a sound similar to running over a styrofoam cup. I looked in my side view mirror and I see I have hit the black bumper of an old BMW. There's black stuff (probably from the old BMW) on my rear bumper just below the strip trim moulding. How can I get that stuff off? Do you think there's any internal damage?