I agree that your comment was rather brusque!
In any event, as a native speaker of English I would say that either order for the adjectives is fine, depending on context. If I had two fast cars and I wanted to say that the one I purchased just last week still has wet paint on it (whereas the one I bought last year is ready to drive now), duo's sentence would give the correct emphasis. Not particularly elegant, but not in any way wrong.
Call me another native English speaker contesting the veracity of the claim.
I think I would add the proviso that your situation wouldn't necessarily call for a comma in English. It would just be "new fast car" and "old fast car." Basically, you're just talking about "fast car"s, so that attribute is more important and has to be closer to "car," hence no comma. You'd get "new, fast car" if you were also talking about an e.g. "old, slow car" and were contrasting on both dimensions but neither really having priority.
I'd be curious if Hungarian has a similar distinction regarding commas.
This is about a fresh paint job?
I understood "not dry" as it "leaks oil". In the sense of "I bought a new sportscar but the damn thing loses oil!".
Is it possible to say "not dry" in that sense? In Hungarian and or English?
I would assume just wet after a car wash might be more reasonable than a still wet paint job?