Whereas the previous M was only available as one model, the M45, the 2006 Infiniti M comes in five flavors. The base model is the V6-powered M35, which is priced at $40,510, including a $610 destination charge. Next in line is the $43,010 all-wheel-drive M35X. One rung higher sits the M35 Sport model, priced at $43,310. But, for those who yearn for a V8, there are the M45 and M45 Sport models, priced at $47,360 and $50,160, respectively. According to Dave Burrows, Infiniti's Director of Operations, the company plans to sell 24,000 Japanese-built Ms annually. The mix is expected to be 30 percent M45s, 40 percent M35 and M35 Sports, and 30 percent M35X models.

Powering the less expensive M35 models is a 280-horsepower V6, featuring a dual overhead cam (DOHC) design, 24 valves, and 3.5 liters of displacement. Max horsepower is reached at 6,200 rpm, and 270 lb.-ft. of torque jumps in at 4,800 rpm, with the motor revving on premium fuel. M45 models house a 4.5-liter, DOHC, 32-valve, eight-cylinder motor that generates 335 horsepower at 6,400 rpm, and 340 lb.-ft. of torque at 4,000 rpm, also operating on high-octane premium fuel.

Regardless of which engine is selected, power is managed by a five-speed, manually interactive automatic transmission. Engineers have added a rev-matching feature that blips the throttle when the manual shift mode is being used. When downshifting, for instance, that blip of the throttle will raise the engine speed, or rpm, to the appropriate level for the lower gear. The result is a smooth transition between gears while using the manual mode of the transmission.

Equally important as the 2006 Infiniti M's powerplants are the standard features that drivers can see and feel. Included are all of the usual luxury car appointments, as well as leather seats with power lumbar support for the driver, genuine Rosewood trim, and a six-speaker audio system with a six-disc CD changer and an MP3 player. Other standard items include a power glass moonroof; a power tilt and telescoping steering wheel; a two-setting memory function for the steering wheel, driver's seat, and mirrors; a trip computer; 18-inch alloy wheels with 245/45 tires; a tire pressure monitor; and electrofluorescent gauges. Finally, there's an ignition system that allows the M to be started with the push of a button when the key fob is located inside of the vehicle, and voice activated controls for the climate system, stereo, and telephones with Bluetooth technology.

Sport models add automatic suspension leveling, a metallic finish that replaces the Rosewood trim, heated and cooled front seats, smoked headlight housings, 19-inch alloy wheels with a titanium finish, Bridgestone Potenza 245/40 tires, a lowered ride height, and adaptive high intensity discharge headlights. This unique lighting system uses sensors that gauge both steering angle and speed, and then turns the headlights accordingly. When rounding a corner, for example, the headlights are turned in the direction of the corner.