This is about new cars, so the condition is expected to be "unused". Of course there's always the possibility of a lemon.

But in terms of how lemons affect negotiation on the used market, there is a classic economics paper, "The Market for Lemons" (summarized here[1]) which you would probably enjoy tracking down.

[1] https://www.wikiwand.com/en/The_Market_for_Lemons