2007 Infiniti M45 Sport

Head-turning quotient:
Bold, deliberately masculine and sinewy.

Body style/layout:
The Infiniti M45 Sport is a front-engine, rear-wheel-drive, mid-size luxury sport sedan that sits at the top of Infiniti's M-series line. Other models include the M45 Base, M35 Base, M35 Sport and the all-wheel-drive M3 X. There is no all-wheel-drive version of the M45 at this writing.

Engine/transmission:
The M45 Sport comes with a 4.5-liter (thus the "M45' moniker) V-8 engine that develops 325 horsepower at 6,400 revolutions per minute and 336 foot-pounds of torque at 4,000 rpm. The engine is linked to a five-speed automatic transmission that also can be shifted manually.

Capacities:
There is seating for five. Maximum cargo capacity is 15 cubic feet. The fuel tank holds 20 gallons of required premium unleaded gasoline.

Mileage:
We averaged 23 miles per gallon in highway travel--not exactly award-winning fuel economy, especially at premium gasoline prices.

Safety:
Electronic stability and traction control are standard, as are four-wheel antilock brakes, side and head air bags.

Price:
Base price on the 2007 Infiniti M45 Sport is $50,500. Dealer's invoice price on base model is $36,438. Price as tested is $53,570, including $2,500 in options (navigation system, backup camera, lane departure warning system and XM Satellite Radio) and a $700 destination charge. Prices sourced from Infiniti and www.edmunds.com.

Purse-strings note:
It's cheaper than a long-term relationship with a shrink. Compare with Audi A6, BMW 5-Series, Lexus GS 430, Mercedes-Benz M-Class.

Complaint:
The lane-departure warning system is an option that should be avoided. It is more annoying than it is protective with its incessant chirping. It becomes maddening on roads under repair or reconstruction where lane markings are redundant or poorly drawn.
Ride, acceleration and handling: Excellent in all three categories. The M45 Sport is one of the hottest dark horses in the luxury-car race --wonderfully quick off the mark, steady as all get-out at highway speeds, and nimble and responsive in curves and accident-avoidance maneuvers. In short, it's remarkably graceful for a car weighing 4,032 pounds.