The US-Canada trade fight is getting worse, which is bad for car buyers, autoworkers, and manufacturers on both sides of the border.

• Canada is hitting back dollar for dollar, matching US tariffs on about $28 billion of American goods starting in September.
• Canada is aiming its tariffs at products made in states that voted for Trump, since it can't hurt the whole US economy.
• Carmakers like Honda are pleading with Trump to stop, because parts cross the border many times before a car is finished and each crossing would get taxed.
• Some manufacturers may just park production in Canada and wait for Trump to back down, which means shutdowns and chaos instead of new US factories.
• Canadians are united behind fighting back, while Americans already dealing with high gas and grocery prices have little appetite for paying more.

Outlook: Expect higher car prices and more disruption rather than a better deal, with US-Canada relations continuing to sour.