Does anybody know how to remove scuffs off of the grey plastic bumper?

hmm.. get it dirty... I would try back to black or some other stuff posted up here.

buy a shrock :-P

That'll take care of it.

If you are really carefull, and I mean very carefull, you can take a propane torch and a fine 3M pad and buff them out. Warm up the scuffs with the torch and then buff like hell with the 3M pad. You can make them disappear.

Or, buy a Shrock bumper.

I think I'll go for the shrock, just have to convince the woman.

shrock-spa baaabyyy !!!!