General Motors and a few other companies make as much as 40 percent of their North American cars and trucks in Canada and Mexico, leaving them vulnerable to tariffs.

The electric car company run by Elon Musk is facing increasing competition, but investors have focused mostly on the prospects for Tesla’s self-driving technology.

Rules for a $7,500 tax break for electric vehicle purchases and leases recently changed, but more far-reaching changes are expected when President-elect Donald J. Trump takes office.

The United Automobile Workers union asked a federal labor regulator to conduct an election at a factory Ford jointly owns with a South Korean battery company.