The rear-wheel drive Boxster is offered in four variants: Base, S, Spyder and Black Edition. The Base gets a 255-hp 2.9-liter flat six-cylinder engine; all other variants get a 3.4-liter flat six-cylinder with direct fuel injection, producing 310 horsepower in the S variant and 320 horsepower in the Spyder and Black Edition. A six-speed manual transmission is standard, while Porsche's PDK seven-speed double-clutch gearbox, including manual shift mode and steering wheel paddles, is optional. The Boxster is outfitted with a power retractable rear spoiler, 17-inch aluminum wheels, LED tail lamps, leather seat trim, air conditioning, cruise control and Bluetooth wireless connectivity, as well as a MP3-compatible CD player and universal audio interface; S trims add 18-inch aluminum wheels and an upgraded sound system. Built from the S variant, the new Black Edition gets a monochrome treatment, with 19-inch black aluminum wheels, black exterior mirrors, blackened tailpipes and black interior trim elements, along with Bi-Xenon adaptive headlights, satellite radio and a navigation system. The Spyder gets exclusive equipment, including a fixed rear lip spoiler, 19-inch aluminum wheels, locking rear differential and leather/simulated suede sport seats with carbon fibre seatbacks; for enhanced performance, the radio and air conditioning are deleted as weight-saving measures. Standard safety features include Porsche Stability Management (PSM), anti-lock disc brakes with brake assist, front and side seat-mounted airbags with a curtain airbag for head protection, and fixed roll-over protection bars. The Porsche Boxster carries over with minor changes for 2012. A new limited production Black Edition debuts, featuring an enhanced equipment level and a monochrome treatment inside and out.