[MP&C]

The black coating the replacement parts come with is hit or miss. Sometimes it hides surface rust underneath or is easily softened by solvents, in which case it should be removed and recoat the panels with epoxy primer. Sometimes it holds up a bit better and people use it without issue. Given the costs of quality automotive paints these days, I'd rather be sure that the substrate and the prep under that is properly done and using quality materials.

Not all paints are the same, but I view 2K primers as your high build, and even though some claim direct to metal adhesion, it is likely not as good as the adhesion you'd get with epoxy primer.. Epoxy is what I spray first to seal off the metal from the elements and to provide a good substrate for anything that follows.