The average price of a new car last year was $30,550, and apparently my neighbors can’t afford it.

That’s the word from Interest.com’s 2013 Car Affordability Study. It ranked 25 cities on the abilities of the people who live there to purchase a new car. The authors of the study started with something they call the 20/4/10 rule. That says you should put down 20%, take out a loan that lasts no more than four years and not use more than 10% of your household’s gross income to make the payment and pay insurance.

The results of the study show that only people living in Washington DC can afford to buy a new car. The median wage in our nation’s capitol is $86,680. Using the 20/4/10 rule the people living there can afford a car worth $31,940. Every other city in the study fell short.

The other end of the scale is Tampa Bay. People with the median salary can only afford payments to buy a car worth $14,516, leaving them last on the list of 25 cities.

While I may love the sunshine and outdoors that Phoenix offers, our median salaries aren’t so hot. The result is that we finished 21st on the list. The 20/4/10 rule says we can only afford the payments for a car worth $17,243.

Of course, the results are a little skewed. Washington DC’s great incomes are swallowed up by the price of an average home. According to this article, it’s currently $437,500, which means you  can only afford the new car if you don’t have a house. No wonder everyone uses mass transit, they can’t afford to put anything in their garage. Both Phoenix and Tampa Bay have average home prices around $114,000 which actually leaves enough room to make a car payment after the mortgage is paid.

Just for the record, I like the 20/4/10 rule. It’s a great way to make sure your car payment doesn’t run you over.