If U.S. President Donald Trump follows through on his pledge to slap 25% tariffs on imports from Mexico it could usher in a volatile new chapter in the longstanding trade relationship with the impacts hitting consumers.

On a sales basis, German automaker Volkswagen is the most exposed to tariff risk, followed by Nissan Motor and Stellantis, S&P Mobility reports.

General Motors, the largest producer of cars in Mexico, won’t provide details on how it would react if President Trump imposes 25 percent tariffs from the two countries.