BEIJING — In his latest criticism of what he sees as unfair trade, Donald J. Trump has taken aim at German cars. Why, the president-elect asked a German newspaper, do so many well-heeled drivers in New York drive a Mercedes-Benz, while Germans buy so few Chevrolets?

Mr. Trump’s question could set the stage for action by his incoming administration against the likes of Mercedes-Benz and BMW, which he criticized for its plans to build a new plant in Mexico. But the president-elect’s musing shows an incomplete understanding of how globalized the auto industry has become since Ronald Reagan went after Toyota and Honda in the 1980s.

That Mercedes-Benz in New York, for example, may have been made in Tuscaloosa, Ala., depending on the model. BMW has a plant in South Carolina that exports 70 percent of the vehicles made there, it says. And Germans might not buy many Chevrolets, which are no longer sold in Germany, but they buy plenty of Opels, which, like Chevy, is owned by General Motors.

Mr. Trump has criticized other companies and industries for moving production out of the United States at the expense of American jobs, such as appliance makers and pharmaceutical companies. But the vehicle industry in general — and particularly foreign automakers, his new target — illustrate how difficult it can be to parse American from international when criticizing global trade.