The Audi A8 debuted on the then-new Volkswagen Group D2 platform, an all aluminum monocoque, marketed as the "Audi Space Frame" (ASF), which helped to reduce weight and preserve structural rigidity. The sedan was offered in both the A8 (standard wheelbase), and the A8L extended or long-wheelbase (LWB) version. The A8L adds 5 inches (127 mm) of rear legroom.
The A8 is available with standard luxury amenities, including dual-zone climate control, wood and leather interior trim, 14-way power and heated seats, and an enhanced Bose audio system.
Source: Wikipedia, 2011