I’d argue it’s stagnant wages plus a rising cost of living creating enough anxiety and depression for conmen to take full advantage of, followed by years of propaganda.
There’s a simple reason why: wages have been stagnant for decades and vehicles have sold for roughly the same prices for decades after adjusting for inflation. When things are further apart you put a lot of miles on your vehicle very fast (easily 10-20k miles a year if you have a relatively short commute and limited social life)
A single vehicle costs about as much as an individual’s median annual income in most rural areas now, and because individual privately owned cars are the only transportation, plus services are far more centralized now (meaning you have to travel to the next town for this that or the other) you truly need 1 vehicle per adult