The muscular M45 enters the new model year with a revised Technology Package, revised Journey Package and revised Advanced Technology Package. Other than these changes in options and trim, it is a carryover for 2007. Buyers can still choose either a 3.5 liter V-6 producing 275 horsepower or a 325 horsepower V-8. The V-6 models can be ordered with standard rear-drive, optional all-wheel-drive or (on Sport models) rear-drive with Active Rear Steering. The V-8 versions can be ordered with Active Rear Steering, which uses electric motors to adjust the geometry of the rear suspension according to steering input and vehicle speed. A five-speed automatic with manual/sport shifting is standard. Standard features include leather seats, rosewood or aluminum trim, an electric sunroof, Intelligent Key with push button ignition, Infiniti Voice Recognition and Bluetooth wireless technology, an in-dash 6-disc changer with MP3 playback capability, plus a Vehicle Information System with 7-inch LCD screen. M35 and M45 Sport versions get 19-inch rims and more aggressive suspension tuning. All models come standard with stability and traction control, anti-lock braking and roof-mounted side-impact curtain airbags. Brake-triggered front seat belts—which tighten under emergency braking—are available optionally. A Lane Departure Warning system, heated and cooled front seats, heated power reclining rear seats and a Bose Studio Surround Sound system with digital 5.1-channel decoding and 14-speakers, including two personal speakers mounted in the shoulders of each front seat, comprise the big-ticket options for 2007.