If you’re part of the shrinking share of Americans who still prefer cars to trucks or SUVs, I have some bad news: Your world is getting smaller. Just two years ago, you could choose from 90 different models, from large to subcompact. By next year, that will shrivel to just 62.

Some of the cars that will disappear from the lineup, including General Motors Co.’s Chevrolet Cruze and Ford Motor Co.’s Focus, will still be manufactured and sold overseas; they just won’t be available to Americans.

This...