Audi says the turning radius of the 2019 A6 is 3.6 feet shorter than the old A6, even though the new one is a little bit longer. How is that possible? Thank, in part, the four-wheel steering system, which helps the newest A6 sedan pirouette in and out of parking spots more easily. The car goes on sale in Europe this summer; expect it in the U.S. by early 2019.