Just giving the wheel arches a bit of a going over in my ute, took a wire wheel to the top layers until i was sure there wasn't any rust holes lurking underneath. There's still a reasonable amount of the original bitumen type underbody protection left, is it reasonable to apply some new stuff over the top without going to complete bare metal?? just dont want to be left with new rust in the future because of a half assed job now. Cheers