Care to cite where you are getting this info from? I seriously doubt the masses are buying $50,000 cars. I live in upper middle suburbia, and the vast majority of cars are well under $50,000. Even the BMWs are mostly below that price range. If the "masses" are buying these expensive cars, I'd like to know where and how many.
One difference between houses and cars: cars depreciate rather quickly, so interest is only a small factor in what you end up paying for your car usage where with houses, interest is a major cost.