Audi S6
Audi made a high-performance, 4.2-litre V8 engine (parts code prefix: 077, identification code: AEC) with a Bosch KE-Motronic ECU available as an option in the original European S4s, and made the decision to continue to do so with the S6, making a version of the 4.2 available as an optional upgrade over the 2.2-litre inline five-cylinder turbo. Unlike the five-cylinder turbocharged version, the V8-powered S6 was supplied with a four-speed automatic transmission as standard, but kept the quattro four wheel drive. A six-speed manual gearbox was also available as an option.
Audi A4
A variant, developed by quattro GmbH, was first introduced in May 2005, named "Audi A4 DTM Edition". It was inspired from Audi's race cars of the 2004 Deutsche Tourenwagen Masters, and was reintroduced in 2006 as a regular option. The 2.0T FSI engine received revised software mapping to the ECU, which increased the output to and of torque. It was available with front-wheel drive, or quattro four-wheel drive.