The storied sports car maker, which was facing challenges from China and slumping demand for electric cars, now has to grapple with tariffs from the Trump administration.

This year was already shaping up to be a tough one for Porsche. Chinese customers were losing interest in the luxury sports car, its bet on electric vehicles was failing with drivers long enamored by the rumble of its combustion engines and its stock price hovered near record lows.

Then President Trump imposed a 25 percent tariff on all cars imported to the United States starting in April. Last week, he doubled down on that, threatening a 50 percent tariff for all products from the European Union, sending Porsche’s shares tumbling further and E.U. leaders and auto executives scrambling to make a deal.

All of Europe’s leading carmakers have been hit by the tariff turbulence when they are already facing increasing competition from Chinese automakers. But