Only minor trim changes distinguish the 2008 BMW 6-Series, which comes in 650i and M6 models, each available in coupe or convertible form. Both body styles seat four. Convertibles have a power soft top and a heated glass rear window that can act as a top-down wind deflector or be lowered for top-up ventilation. The 650i models have a 360-hp V8 and offer a choice of a 6-speed manual or 6-speed automatic transmission. The M6s have a 500-horsepower V10. It's available with a 6-speed manual or a 7-speed automated manual transmission. The 7-speed is a manual transmission that has no clutch pedal. Gear changes take place via the floorshifter or steering-wheel paddles, and it can be set to shift like an automatic. All models have ABS, traction control, antiskid system, and BMW's Active Roll Stabilization designed to counter body lean. Also standard is BMW's Dynamic Drive Control that adjusts suspension, throttle, and SMT/automatic-transmission settings for sportier response. BMW's Active Steering, designed to quicken low-speed steering response, is standard on M6s, available on 650s. M6s also include a driver-adjustable suspension, uprated brakes, and larger wheels. Front side airbags and front knee airbags are standard; coupes add curtain side airbags. All models come with navigation system, steering-linked headlights, and BMW's iDrive controller for climate, audio, and navigation functions.