Has anyone ever bought fender flares from performance products?... they claim they are primed and ready for painting but nothing of the sort. Right now my body shop is stripping the stupid things and sanding it down FINE and then painting them. I heard just priming them and then painting will eventually just make the paint strip away. Any one have any suggestions? We're sanding with 400 then 600 then 800 then 1000 so we taking it right down.