On the evening of March 31st, Elon Musk unveiled Tesla’s sinuous Model 3, the company’s first “affordable” electric-car model. After touting the sedan’s punchy acceleration, two-hundred-and-fifteen-mile battery range, and sweeping, seamless glass roof, he mentioned its base price of thirty-five thousand dollars and told the audience that prospective buyers had already reserved more than a hundred and fifteen thousand of the vehicles, to rapturous applause and shouts of “You did it!” Not one to miss…