Good point Davis, the 3M machine glaze is good stuff.

I had two small, but noticebale scratches (relatively deep) on the front pass. door and rubbed it out by hand. This was NOT a great idea, as my arms aren't Porter Cable polishers. This left some "hazy" marks, but my wife and I just detailed the Benz today (swirl remover, polish and wax) and they came out fine. So... if those scratches can be eliminated, 3M's product should clear up hard water marks too.