As a direct competitor to the Mercedes E63 AMG and BMW M5 which have both been presented a while ago, Audi is planning to offer the RS6, the estate variant of which is seen here undergoing final tests at the German Nürburgring. The bigger air intakes in the front bumper, the wider fenders and the diffuser at the rear are the key clues. While the S models have four round exhaust pipes, the RS models will receive oval pipes as their distinguishing feature.
Shown in these spy photos is the saloon, but the new RS6 will also be available as an estate. Powered by the same V10 engine as the S6, but with some help from a turbo delivering about 520-550 bhp, this Audi will give the M5 and E63 AMG a strong challenge. The RS6 will debut in Frankfurt in September this year.
Source: http://www.evo.co.uk/news/evospyshots/209994/audi_rs6.html
