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.

The tariffs imposed by Trump were seen by some as an existential threat to the auto sector. Arthur Laffer, whom Trump gave the Presidential Medal of Freedom to during his first term, said in a private analysis that the tariffs without any modifications could add $4,711 to the cost of a vehicle.

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