Michael Mauer is hiding a deep, dark secret. “My first car?” He repeats my question, his eyes shining with a mixture of nostalgia and the fear of being somewhat outed. “Actually, I had a green Nissan 160? says the man who’s responsible not only for making modern Porsches look good, but is also the head of design for the broader VW Group. “There were really not that many cars on the road in Germany back then, and the Nissan had two advantages. First, it was really cheap. And second, it had 85hp, at a time when all of my friends...