I have tried everything to keep my iBooks, and now macbook, clean. It seems they always become dingy after a bit, and black marks are common also. Nothing I have used has effectively taken them back to "showroom clean". I've tried all the oxy cleaners, glass cleaners, plastic cleaners, you name it - I've tried it. Today I decided to take the lady of the house up on a bet. She proclaimed that the Mr. Clean magic eraser will clean ANYTHING. I told her that my Macbook and iBook wouldn't come clean I'd tried everything short of sandpaper to clean them and they remained dingy with little black marks here and there. She bet me $5 that this magic eraser could make them look like brand new and erase ANY marks on the case, that's black marks and all. Well, I lost my $5.............. I had marks on this thing that I swore were down in the plastic. Deep black scuffs. It looks like brand new. I dare you to try it and report back.