Some of you might know how to do this already, but if anyone's interested I found this very inexpensive method of smartening up my bumpers, which were pitted with rust.
Basically, you need Cola and aluminium foil. Put some Cola in a bowl and rinse the bumpers using the rest. Now scrunch up some foil (shiny side outwards if poss), soak it in the Cola in the bowl and rub your bumpers with it, paying particular attention to the rusty parts.
I couldn't believe the results! I went from this:

To this:

Well chuffed!!

I was worried the foil might scratch the bumper, but it didn't. I finished off by rinsing, drying and polishing with metal/chrome polish (Autosol). Worked out way cheaper than buying new ones!
Edited by lewBlew, 05 July 2012 - 08:24 PM.