I would dare to use the old addage of "supply and demand". If you can get more money for the same car...why not.
I would also say that median household income (varies at different parts of the country) which is a factor of the local cost of living, has much to do with it.
Let's say that a married couple earns $200k in Southern California and live in a home that is valued at $800k. It's not to hard to sell them a $45K car.
Those same people, in another part of the country, would earn say about 1/2 of that (not trying to insult anyone, just trying to illustrate; allbeit extreme). It then becomes harder to sell that car at that price.
I do live in So. Cal. and find it amazing what people pay for cars vs. homes and incomes. I can't fathum making a $500 payment for a car if I had to pay $1000 (or less someplaces) for a mortgage (Square footage being equal). Then insurance, fuel, tires, etc. on top of that. If you had the "inflated" incomes of these select areas of the country then these other expenses seem minor. And a vehicle would only be 10% of total annual income vs. 30% (again, just a crude illustration; an attorney would like me to state "actual percentage will vary")
So in a strange twist of economics, it's actually easier to afford a Lexus here in So. Cal because the cost of living is higher.
I think it goes like this:
Higher cost of living=higher income=more disposable income=higher asking prices for vehicles. I'm not sure I totally understand it either; but it sure feels that way out here.
My humble opinion.