I'm sorry, but your example makes no sense. For a $10,000 car, financed for 5 years to require $500/month means the interest rate would have needed to be over 56%/year!

No way anyone financed a car at that interest rate anytime in the last 40 years unless they did it through a payday loan place or a loan shark!

A 5-year loan starting at $10,000 with a 6% APR would result in a $190.61 monthly payment. That would total to $11,627.19, with total interest payment of $1,627.19 or an average monthly interest of just $27.12.

That undermines the whole premise of this article. You don't need to be able to pay cash for a car to be "able to afford it." As long as the interest payment isn't so extreme that it gets in the way of other priorities, an auto loan is fine if it lets you buy a reliable car that you need.