Looking for a new car under $20,000? Good luck. Just 1 remains

ViewJust five years ago, a price-conscious auto shopper in the United States could choose from among a dozen new small cars selling for under $20,000. Now, there’s just one: The Mitsubishi Mirage. And even the Mirage appears headed for the scrap yard.

At a time when Americans increasingly want pricey SUVs and trucks rather...