With his bespoke pinstripe suits and 1960s-style sideburns, Stephan Winkelmann embodies Lamborghini’s raging-bull image. A German-born businessman raised in Italy, Winkelmann became CEO of Automobili Lamborghini S.p.A. in 2005, after the company fell under the auspices of Audi, and soon introduced German precision to the Italian marque’s rough-and-tumble cars. “Lamborghini …