Lithe and limber, Infiniti's "M" hides its four-door character in the guise of a coupe. A newcomer last year, it adds refinements for 2007 in this rear drive-based sport sedan that pumps out power, sleek visual punch and a selection of dessert amenities and high tech that Infiniti terms "intuitive" technology.

In a sort of "M" and "M" offering, the vehicle comes in two flavors. There are three versions of the M35 in rear or intelligent all-wheel-drive, based on a 3.5L V6 (275-HP) powerplant. The M45 gets a gutsy 4.5L V8 rated at 325-HP in either a luxury or a sport model with Rear Active Steer.

Among 2007 adds is a new Advanced Technology Package, plus more standard equipment. All models come with leather seating, five-speed automatic including manual mode with downshift rev matching, power-sliding sunroof, advanced airbag system and 10-way power seating for driver and front seat passenger. Inside are such standards as Intelligent Key with push-button start, power lumbar adjustments, and Bluetooth technology for all those techy electronic entertainment and telephone connections.

The M vehicles are designed to meld luxury and performance, with a front-to-rear weight balance meant to enhance precision maneuvers. They are based on the same "next gen" underpinnings as Infiniti's sporty G35 sedan and FX premium sport utility.

Pampering comes from such goodies as genuine Rosewood and aluminum trim, available heated power reclining rear seats, and advanced Bose sound system with dual front seat shoulder mounted personal speakers among the 14 on board.

M35 models, prior to options, range from $41,450 to $44,550. The M45 is $49,100 ($50,550 for sport model). The priciest option: Premium package with satellite at $8,900. Best mileage estimates are 18 city/25 highway for the M35, and 17/23 for the M45.

Among safety options are Intelligent Cruise Control, RearView Monitor and voice activated nav system. Drivers who grow drowsy can have an added safety net. There's an available Lane Departure Warning system that gauges a driver's speed and direction and signals when it is drifting out of lane, a major cause of fatal head-on collisions.