Audi's new premium compact four-door hatchback debuted as an early 2006 model, with front-wheel drive and a four-cylinder turbocharged engine. A V6 model with all-wheel drive joined later. Slightly smaller and less expensive than Audi's A4 compact sedan, the A3 shared some underskin design with the Jetta and Golf from Volkswagen, Audi's parent company. Competitors included the Acura TSX, Saab 9-3, and Volvo V50 wagon. The front-drive 2.0 T held a 200-horsepower turbocharged four-cylinder engine, while the 3.2 S line quattro had a 250-hp V6 and Audi's AWD system. A six-speed manual transmission was standard on the 2.0 T. Optional on the 2.0 T and mandatory for the 3.2 quattro was Audi's Direct Shift Gearbox (DSG), which was a sequential manual transmission (SMT)--essentially a manual gearbox without a clutch pedal. Gear changes were controlled via a floor lever or steering-wheel paddles, or the DSG could be set to shift like an automatic transmission. Antilock four-wheel disc brakes, traction/antiskid control, and 17-inch wheels were standard. Also standard were front torso side airbags and head-protecting curtain side airbags. Rear torso side airbags were optional. All A3 models had split folding rear seatbacks. Leather upholstery, sport front seats, alloy cabin accents, and a sport-tuned suspension were standard on the 3.2 and optional on the 2.0 T. Both models could have a navigation system, satellite radio, and Audi's Open Sky System, essentially a full glass roof incorporating a power sliding glass sunroof over the front seats.