U.S. automakers are set to get a break on some of the sweeping tariffs President Donald Trump is imposing. Yet even with the new waivers, the outlook for America's longest-lived carmakers remains cloudy, with General Motors saying Tuesday it was "reassessing" its earnings guidance in light of the uncertainty over the tariffs impact.

A slower phase-in for tariffs on auto parts will give manufacturers time to ramp up manufacturing in the U.S. Some warn they will still drive up car prices.