The Panamera is offered in five versions, the rear-wheel drive 2 and S, and the all-wheel drive 4, 4S, and Turbo. The 2 and 4 models come with a direct injection 3.6-liter V6 300-hp engine while the 4, 4S and Turbo feature the larger 4.8-liter V-8; the S and 4S models making 400-hp, whereas the Turbo adds twin-turbocharging for 500-hp. The Porsche PDK double-clutch gearbox is the only transmission choice, and all models are equipped an auto start-stop feature for increased urban fuel economy. The body appears to be a four-door sedan but with a coupe-like profile and a power liftgate, rather than a typical trunk, for access to the spacious luggage area. Standard safety features include ten airbags, bi-xenon adaptive headlights with LED daytime running lights, rain sensing wipers, full LED rear lighting, four belt pretensioners and electronic traction and stability control. A small sample of optional tech features includes a 6-disc CD changer, Bose surround sound, Burmester surround sound, front and rear ParkAssist, an electronic logbook and voice control. For 2011 the Panamera has added V6 models to round out the line-up.