Even if you buy your cars cash, unless you already have that much liquid sitting around you've gotta be saving hundreds every month to prep for the next car and for major repairs to the current car. You're either saving hundreds a month for future car expenses, already have a large savings (so, not these folks), or you're 100% for sure guaranteeing future debt.

[EDIT] which is to say that even without a car payment, you better be saving the equivalent of at least half a car payment a month, or you're probably falling behind.