But it is a bubble with a feedback loop. (i) car manufacturers are big enough parts of the market that they can buy up used cars and scrap them/export them, pu

But it is a bubble with a feedback loop. (i) car manufacturers are big enough parts of the market that they can buy up used cars and scrap them/export them, putting the cost of that onto new cars (ii) they can lobby government to introduce environmental standards. Japan exports a good part of its used cars because of the cost of maintaining a used model. The difference with cars over houses, is that cars are mobile. So the issue, if there is one, is just the usual one of over-lending via agency originators and securitising those bad loans onto muppet pension funds searching for yield. But that's not unique to the car market.