February numbers show the U.S. electric-car maker is struggling to attract buyers in the region. Mr. Musk’s politics aren’t helping.

Tesla Inc.’s registrations plummeted in Germany last month as Chief Executive Officer Elon Musk irked voters taking part in the country’s closely contested federal election.

Tesla saw its sales volume in Germany decline by more than three quarters in February, according to the German road traffic agency KBA, even though sales of electric vehicles picked up overall.