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 new actions Trump signed allow reimbursements for domestic car producers importing car parts, which will be subject to 25% tariffs starting May 3. The maximum reimbursement will be 3.75% of the value of domestically produced cars. The cap will decrease to 2.5% for the second year and be phased out entirely thereafter.

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.