Audi RS 6
The Audi RS6 quattro, commonly referred to as the RS6, is the highest performing version, and top-of-the-line specification of the Audi A6, positioned above the Audi S6. It is a mid-size sports-focused executive car, produced by the high performance private subsidiary company quattro GmbH, for Audi AG, part of the Volkswagen Group.
Both versions of the RS6 are, or have been produced as, a five-door five-seat "Avant", Audi's name for an estate car–station wagon, along with a four-door five-seat saloon–sedan. Furthermore, their internal combustion engines are all front-mounted, are longitudinally oriented, and are not shared with any other vehicle. The transmission is mounted immediately at the rear of the engine in a longitudinal orientation, in the form of a transaxle.
Production of the original Audi C5 RS6 began in June 2002 and ended in September 2004. The second and current Audi C6 RS6 was introduced at the 2007 Frankfurt Motor Show. The original RS6 (C5) was the first Audi RS model exported to North America, while the succeeding C6 RS6 is only sold in Europe.
Source: Wikipedia, 2011