It's more that in America, cars are for the most part an inelastic commodity. It's very, very hard to hold a job and maintain your life without a car except in the densest of metro areas. Since the population is still growing, sales of cars keep going up and people get trapped in predatory loans or conditions. Used cars are also harder to find and more expensive, which pushes people into these predatory conditions.

I think it's a really poor indicator for the future. America literally cannot function without cars, and if people cannot afford cars they cannot afford to work.