Higher prices will deter buyers and force automakers to curtail production, said Jonathan Smoke, chief economist at Cox Automotive. He forecast that U.S. factories would produce 20,000 fewer cars per week, about 30 percent less than usual.

If the taxes are fully passed onto consumers, the average price on an imported vehicle could jump by as much as $12,000.

The tariff will take effect April 2, and expects say it will jack up new car prices between $3,000 and $12,000.