As I read your post above I thought about xpo 04.As I was walking past the zymol truck Chuck and our own Joe L. of Vinces autobody were spot detailing a black 91 or 92 and discussing the subtle pitting and irregularities of some of the panels and paint(some of which the owner was aware of ,some not),to the owners surprise it was the experts opinion that the car had been repainted in spots.I have seen many unmolested(over 50k miles) older cars at xpos through the years,and can attest to the high quality of the stock paint.Corosion afaik is verrry subtle in our cars that have not seen prior damage.