Well, actually painted plastic, even when used with a binder can chip as easily, if not easier than painted metal. Just an idea, I still have a roll and have been thinking of using some spot repair and covering the underside of my front bumper. I've been trying to figgure out how to remove the stocker fogs... and it's a trip down there... friggen black plastic pandoras box. While trying to look at that I noticed how scratched my bumper is...

 

I'll let you know if I have a problem with chipping on the guards....so far no problems.

 

I know this is an old post but does anyone have a link to some splash guard installed pictures? All the ones in this thread are dead.