When I was young and couldn't afford new vehicles, I bought them new. Now that I'm older and can afford new, I buy used, and keep them as long as I can.
That's part of the reason, but it doesn't explain the spike in the age of the average car, from 9 years to 11, since 2007, the last year of Bush's term in office.
It's another symptom of the Obamalypse.
I’ve grown rather fond of Mazdas myself; mine’s a ‘91 Miata with 293K on the clock AND its original engine.