Used 2007 INFINITI M45

Though the 2007 Infiniti M45 doesn't quite match the competition in terms of luxury and refinement, it's a winning choice for those whose priorities are oriented toward performance.

Everyone likes to witness a good metamorphosis. They impart a spirit of hope and leave us with the sense that anything is possible. As far as automotive metamorphoses go, few have been more dramatic than that exhibited by the Infiniti M45. The car began life as a wallflower; it offered lots of value for the money but was short on sex appeal and outgunned by the competition in terms of style, features and interior room. Infiniti brought the car in for some much-needed revisions, and in model-year 2006, the M made like a butterfly and spread its wings as two dazzling, all-new sedans -- the M35 and M45.

With its sculpted lines, the 2007 Infiniti M45 boasts all the requisite aesthetic upgrades that come with any good redesign, but its makeover is about more than mere appearances. The car has been endowed with a more spacious cabin, one that offers more front head- and legroom than others in its class. The M45's interior design cues are a bit busy when compared to those of competitors like the elegantly understated Lexus GS 430. But overall, the car's cabin is well-built and attractive, and we have no doubt that most folks will be more than satisfied with what it has to offer.

Without a doubt, the M45's most appealing feature is its sporty persona. The muscle-bound 4.5-liter V8 is good for 325 horsepower and 336 pound-feet of torque, and is as solid an engine as you'll find in this segment. Power delivery is explosive, low-end torque is abundant and it's smooth enough to feel at home in a sedan with a six-figure price tag. The suspension is pleasingly firm and the car feels balanced when driven aggressively. The steering is also impressively quick on the Sport model, as it comes with an active rear-steering system.

Relative to the competition, the M45 trails when it comes to refinement. Those seeking a choice with maximum polish will be happiest with a car like the Acura RL, Lexus GS 430 or Mercedes-Benz E550. But the 2007 Infiniti M45 takes top honors for being the true driver's car of its class. If you're an enthusiast, you'll find this Infiniti's bravado downright irresistible.

The 2007 Infiniti M45 comes in two flavors: base and Sport. Standard on the base trim are 18-inch alloy wheels, a 10-way power-adjustable driver seat, Rosewood trim, leather upholstery, one-touch up-and-down power windows, dual-zone automatic climate control, an auto-dimming rearview mirror, heated outside mirrors and a 160-watt, six-speaker sound system with a six-CD changer with MP3 playback capability. The Sport trim substitutes aluminum accents for the wood ones and adds 19-inch alloys, a sport-tuned suspension, an active rear-steer system and adaptive HID headlamps.

Available packages add a navigation system, voice-recognition technology, a center-console-mounted DVD player and adaptive cruise control. (This system senses vehicles ahead and adjusts your speed to maintain a selected following distance.) Among the other extras are a lane-departure warning system and a 14-speaker Bose surround-sound audio system.

The rear-wheel-drive M45 is motivated by a brawny 4.5-liter V8 that's capable of 325 hp and 336 lb-ft of torque. A five-speed automatic with automanual capability and downshift rev-matching is standard. An M45 that we tested hit 60 in 5.7 seconds and completed the quarter-mile in 14.4 seconds.

The M45's suite of safety features includes ABS, stability control, front active head restraints, front seat side- and full-length side-curtain airbags. An available lane-departure warning system alerts the driver of unintended lane drifting. In IIHS crash tests, the 2007 Infiniti M45 scored a "Good" rating – the highest possible – in both frontal and side impact protection.

The V8 engine in the 2007 Infiniti M45 provides gobs of low-end torque and smoothness. Power delivery, either out on the highway or off the line, is outstanding. Braking performance is impressive, and a firmly tuned suspension provides excellent balance in the corners. The trade-off is that the car, especially in Sport trim, can feel a bit raw around town as the suspension can be unforgiving over large road irregularities.

The M45's interior is sportier than that of others in its class, with firm, heavily bolstered seats, a can't-miss-it tachometer and real aluminum (in the Sport model) trim. The car's décor isn't as streamlined and eye-pleasing as that of rivals, however. Gauges are lit in a less-than-ambient orange and the center stack controls are a bit busy. Additionally, the Infiniti name and logo are embroidered on the seats, a touch many on our staff found a bit over the top. All in all, though, the M45's cabin is pleasant and well put together, and we have no doubt that most will be more than happy to spend time in it.