The 25% tariffs on imports from Mexico and Canada are likely to increase costs for Stellantis, making its products less competitive compared to Asian and European automakers who may not face similar tariffs. This could lead to a short-term negative impact on Stellantis' stock price as investors anticipate potential declines in sales and profitability in the U.S. market. The company's engagement with the Trump administration indicates efforts to mitigate these impacts, but the outcome remains uncertain.