For nearly twenty years, Audi Sport was known as quattro GmBH, but with cars like the 2018 RS 3 the performance division is embracing its more public persona. There's brand equity in "Audi", and Stephan Winkelmann, Audi Sport's CEO is under no illusion about how much potential that has for his line-up of unusual, rip-roaring cars. Winkelmann's next job, he …