In all its post Volkswagen-era models, Audi has firmly refused to adopt the traditional rear-wheel drive layout favored by its two archrivals Mercedes-Benz and BMW, favoring either front-wheel drive or all-wheel drive. The majority of Audi's lineup in the United States features all-wheel drive standard on most of its expensive vehicles (only the entry-level trims of the A4 and A6 are available with front-wheel drive), in contrast to Mercedes-Benz and BMW whose lineup treats all-wheel drive as an option. BMW did not offer all-wheel drive on its V8-powered cars (as opposed to crossover SUVs) until the 2010 BMW 7 Series and 2011 BMW 5 Series, while the Audi A8 has had all-wheel drive available/standard since the 1990s. Regarding high-performance variants, Audi S and RS models have always had all-wheel drive, unlike their direct rivals from BMW M and Mercedes-AMG whose cars are rear-wheel drive only (although their performance crossover SUVs are all-wheel drive).