The new C6 generation A6 was released in 2004. Designed by Walter de'Silva, the new model is visually an evolution of the C5, but is lengthened to 492 centimetres (193.7 in), incorporates the new Audi trademark "single-frame grille", and features more sophisticated technology. Most notable is the Multi Media Interface (MMI), which is a system controlling in-car entertainment, satellite navigation, climate control, car settings such as suspension configuration and optional electronic accessories through a central screen interface. This has the advantage of minimising the wealth of buttons normally found on a dashboard by replacing them with controls which operate multiple devices using the integrated display.
On the internal combustion engines, the new Fuel Stratified Injection (FSI) direct injection technology was introduced. Although the line of engines represents the same progression as the former model, all engines were new. The multitronic continuously variable transmission continues as an alternative for front-wheel drive models, alongside a new six-speed tiptronic automatic transmission available in the four-wheel drive models. Audi's "trademark" Torsen-based quattro permanent four wheel drive is available in most of the lineup, and standard in the most powerful models.
Source: Wikipedia, 2011