Jonathan Gitlin

BARCELONA, SPAIN—In one of the most elaborate new-car reveals the industry has seen, Audi has revealed its new technology flagship to the world. The big three German luxury brands (Audi, BMW, and Mercedes-Benz) are locked in a constant battle of oneupmanship when it comes to these four-wheeled standard bearers. As each brings out a new super-sedan, it leapfrogs its rivals in terms of features and technology, and the fourth-generation A8 is no exception.