When I was in Colorado, there was a European car shop right next door to my business. He said some of the best used vehicles you can buy are lease returns from those three manufacturers. They all have some sort of required scheduled maintenance, plus any warranty work, that takes place in the 36 or 48 month duration of the lease. I think Audi (though not generally prone to lemons) is on that list now as well. Most of the ‘bad’ is worked out of them by the time they’re turned back in and they make great cars at a discounted rate for the level of vehicle you’re getting. All of his personal vehicles were 3 year+ old Land Rovers and they were solid. Buy one that wasn’t in one of those programs and you’re really taking your chances. I bought one of his 10 year old Land Rovers that was nearly bullet proof and other than tires and oil changes, didn’t need much of anything for the ten years I owned it.
To your point, the cars in the smaller lots are either bought by the dealer at auction or taken in trade for one of their other pieces of shit. They don’t typically have or care about maintenance records or the condition of the vehicle beyond being able clean it up and keep it running long enough to sell it. I know ‘As Is’ covers a lot, and I’m generally not a fan of Government involvement in much of anything, but I’d like to see some sort of minimum requirements for pre sale inspections with a 30 to 90 day return window for complete failures like described in the OP. There has to be some protection for the dealer as well, because people are generally stupid and will do dumb shit with cars/trucks all the time.