The Audi RS6 will be available in a sedan body style after a long gap of 15 years. The new-gen RS6, which is currently under development, will be the first RS6 sedan since the C7 from 2011.
A test mule of the upcoming RS6 sedan was recently spied testing for the first time, as Audi prepares to take on the mighty BMW M5 and Mercedes-AMG E63.

The new Audi RS6 will be based on the Premium Platform Combustion (PPC) architecture. As expected, the RS6 sedan has a sporty exterior, featuring large vents, dual exhausts and wide fenders, housing the signature RS wheels. It also gets upgraded brakes with massive rotors at all four corners.
The new RS6 could get a plug-in hybrid V6 under the hood. Some reports also talk about the possibility of a twin-turbo V8 plug-in hybrid setup. However, the last time Audi built an RS6 sedan, it was powered by a 5.0 liter twin-turbo V10 engine producing 571 bhp and 479 lb-ft of torque.
The new RS6 will also be available in Avant (station wagon) body style when it arrives sometime next year.
Source: Carscoops