The Audi RS 4 is the high-performance variant of the Audi A4 range produced by Audi Sport GmbH for AUDI AG, a division of the Volkswagen Group. It sits above the Audi S4 as the fastest, most sports-focused car based on the A4's 'B' automobile platform. The RS 4 was reintroduced in 2012, based on the A4 Avant instead of the sedan as did the original model. The original B5 version was produced only as an Avant, Audi's name for an estate car/station wagon. The second version, the B7, was released initially as a four-door five-seat saloon/sedan, with the Avant following a short while later. A two-door four-seat Cabriolet version was subsequently added. The 'RS' initials are taken from the German RennSport—literally translated as 'racing sport', and is the Audi marque's highest trim level, positioned above the 'S' model specification of Audi's regular model line-up. Like other Audi 'RS' cars, the RS 4 pioneers some of Audi's latest advanced technology. It is only available with Audi's Torsen-based 'trademark' quattro permanent four-wheel drive system. (Source: Wikipedia.org, CC BY-SA)