With the superior rest protection modern cars have its less of a worry but in the 80’s and 90’s metallic paint resisted the ravages of time better than non-metallic. Base red still fades though and lacquer peel is still an issue particularly in Japanese cars which is one of the few weak points. I still see fairly modern Honda’s and Toyota’s suffering peel and red examples fading very early. The Europeans still show the way here. I wouldn’t be too concerned either way if you buy a nice example and give it a polish from time to time it’ll retain its looks well into old age. The paint on both my 7yr old Polo (white) and 9yr old Avensis (grey metallic) is in excellent condition with no peeling and no visible rust at all.

Weird - I've seen far more European cars of the base red colour that are faded than Japanese ones, the worst being 1990s to mid 2000s Vauxhalls. I think that most Post Office vans are Euro ones of many varieties, and very few of those are not faded, even the latest ones. It could be certain shades of red that are more susceptible, e.g. Post Office red and lighter, rather than darker shades.