I used "Goof Off, The Ultimate Remover" yesterday. Works great, the crud wipes right off. Works good on propane tank covers too. However the can says "DANGER!: FLAMMABLE LIQUID AND VAPOR. EYE IRRATION, HARMFULL OR FATAL IF SWALLOWED. I wore rubber gloves and washed the caps very well with soap and water after using the Goof Off. But it does work!
2010 Rockwood 2604SS
2008 Silverado 1500 LTZ 4X4
Great Wife and Idiot Yorkie
True Friends are like diamonds, precious and rare.
False ones like autumn leaves found everywhere