Tesla Inc.’s sales plummeted 59% last month in Germany, adding to indications that Chief Executive Officer’s Elon Musk political activities are hurting the carmaker’s business in major electric vehicle markets.

Tesla sales careened lower in Germany in January, as sales of the electric-vehicle company headed by Elon Musk tumble across Europe. The German trade group VDA reported that Tesla new-vehicle registrations fell 60% in January,