POR15, undercoat, or sprayon bedliner?

sounds like we are on the same page if the metal was prepared properly it is you preference of what your application would be to presreve that.

and franktiregod a car in primer is another evil for sure primer is pores. it is noyhing but a spunge it will absorb all the moisture in the world and as so many of us have seen the rust will then bleed through