Audi TT ultra quattro concept Audi is turning the Wörthersee 2013 into the “Home of quattro”. At the large gathering from May 8 to 11 in Reifnitz (Kärnten), the premium brand will unveil the Audi TT ultra quattro concept – which combines minimal weight and maximum sportiness. A wide range of high-performance cars will also give fans another taste of sportiness. In addition to the legendary Sport quattro S1, the very latest RS models and…