Audi's aluminum flagship is offered with short and long wheelbase models. The A8 and A8L have a standard 4.2L V-8 with 350-bhp, or buyers can choose the optional 450-bhp W-12 engine (A8L only). All models have quattro(R) AWD. A Bang & Olufsen 1000-watt audio system is available. The range-topping S8 features a 450-bhp 5.2L V-10, sport suspension, 20-inch wheels, and sport seats. The S8 features an aluminum chassis, and standard quattro(R) AWD. A Bang & Olufsen 1000-watt audio system is available.