Undercoating

[dr. d]

this is my problem https://i.ibb.co/yRSVH9H/20190522-092834.jpg

it appears to be originating from under the paint.
undercoating it will probably hide it until it has eaten thru the metal, whereupon it will probably cost considerably more, to fix.

just eyeballing it, it seems to be pretty well-protected from trauma. the only reason i can think of, is that the rust was already there from the start... i do not think undercoating is needed for further protection, after the rust had been removed and the metal, re-painted.

so i wonder,
does mitsu practice quality factory rustproof?