Once you get the stains off with the Mothers, go and throw the S-100 into the garbage. That stuff is junk. The engine brightener is okay, but the cleaner is terrible. It is very harsh and leaves spots. Spots on black plastic never come off.
I agree with you Glider, but why take the chance that you don't get it off fast enough when there are better products and methods to clean the bike. Also, instructions require bike to be cold.