Tesla reported a surprise increase in sales in the third quarter as the electric car maker likely benefited from a rush by consumers to take advantage of a $7,500 credit before it expired on Sept. 30. The company reported Thursday that sales in the three months through September rose 7% compared to the same period a year ago. The gain follows two quarters of steep declines as people turned off by CEO Elon Musk’s foray into right-wing politics avoided buying his company’s cars and even protested at some dealerships. Sales rose to 497,099 vehicles, compared with 462,890 in the same period last year.