 The U.S. is already putting in place tariffs in an effort to prevent cheap Chinese electric vehicles from flooding the U.S. market. But American car companies may have another worry. Many of the Chinese car makers may be preparing to set up shop in Mexico. It could be part of an effort to exploit North American trade rules. Stocks were virtually unchanged today. The Dow up 36 points. The Nasdaq rose 53 points. This is NPR.