used car dealer here so obviously im biased to this comment.

but carvana has tried the vending machine approach and it didnt work. something about people needing someone to talk to through the process and after sale issues. (should there be any) I believe i add a lot of value to the equation and I am the
ONLY solution to any issues for my customer.
as for the op-
gap is not for repos. its for total loss claims. "extended warranty" is a euphemism for VSC, vehicle service contract. legally we are not allowed to call it a warranty, because only the mfg can warranty the product.
having been on multiple sides of the vsc industry: as an adjuster for one of the countries largest vsc companies, as a dealer selling them and also a dealer servicing them.....I consider myself somewhat of an expert. kind of like sleeping at a holiday inn kind of expert. so here are the basics. there are two types of vsc contracts and only two. inclusionary and exclusionary.
1- inclusionary- this is likely the most common type(on used cars) and most often the type that gets the industry a bad rap, due to it ONLY covering parts that are listed in the contract. no one, and i mean NO one ever reads the contract or is in possession of the damn thing. so when the fog light leaks(like mentioned in a previous comment) and the owner expects the "warranty" I bought to cover it.....then they're pissed off because its not a "stated part" in the contract. its not the vsc companies fault the buyer was not aware of what the actual coverage was. that's on the dealer that sold it and the buyer.
2-exclusionary- this is most often sold along with new cars beside the oe warranty. I can also sell it on newer used cars, typically still in some form of oe warranty. ie- a 2022 with 50k on it, still under the oe powertrain warranty. this coverage mimics the oe bumper to bumper coverage EXCEPT for the items listed as "excluded", which typically are wear items. brake consumables, belts, hoses, etc. ( i have a company that will cover "wear items" also) BUT...... back to the foglight above. this contract will probably look at that leak as a crack from damage and not an actual part failure, so I would not be surprised that it may not cover it.
tldr- caveat emptor mfr's