When Infiniti brought out the G35 sport sedan and sport coupe four years ago, it was easy to see who the company was going after. With its powerful six-cylinder engine, rear-wheel drive and finely balanced, sport-tuned chassis, the G35 didn't gingerly dip its toe into the entry-level luxury sport sedan/coupe waters. Rather, it took a flying leap, did a cannonball and splashed cold water all over the BMW 3 Series.

At the time, we gave critical praise for the Infiniti G35's style, strong performance and roomy cabin, while the few criticisms involved some lackluster cabin materials, over-assisted steering and the lack of a manual transmission in early sedan models. With the increased availability of a six-speed manual and the introduction of an all-wheel-drive model, the G35 saw its already considerable popularity rise as the years went on.

For 2007, Infiniti has brought out a fully redesigned G35 sedan, while the coupe remains unchanged for now. Key improvements for the sedan include even more power from the already muscle-bound 3.5-liter V6 (306 horsepower versus 293 or 275 in the coupe), an updated and stiffer version of the car's "FM" platform architecture, sharper handling, a mild but complete styling makeover and welcome improvements to interior material quality. A few new features debut for the sedan as well, such as active four-wheel steering, adaptive cruise control, a rearview camera and a rev-matching feature for the automatic transmission's manual shift mode.

Despite standing pat for this year, the Infiniti G35 coupe remains a strong entry in the sport coupe segment, with its handsome styling, fleet-footed personality and relative bargain price tag. Many think of it as a four-seater Nissan 350Z, with which it shares its basic platform.

Either way, the 2007 Infiniti G35 is a must-drive for anyone considering a top entry-luxury sport sedan or coupe. Key competitors include the Audi A4, BMW 3 Series and Lexus IS 350. With more room and power than its German rivals, a more spacious cabin than the IS and a lower price tag than all three, we expect the G35 will attract plenty of attention this year.

The 2007 Infiniti G35 comes as a midsize sport coupe and sport sedan. The sedan offers five trim levels: base, Journey, x (AWD), Sport and Sport 6MT (six-speed manual transmission). The base G35 comes with 17-inch alloy wheels, bi-xenon HID headlights, leather seating, front power seats (eight-way driver, four-way passenger), automatic climate control, full power accessories, a CD player, a trip computer and keyless entry and start. The Journey adds dual-zone climate control and a six-disc CD changer. The x adds all-wheel drive and heated front seats. The G35 Sport has the Journey's equipment and adds firmer suspension tuning, 18-inch alloy wheels, a limited-slip rear differential, front sport seats and a sport steering wheel. The Sport 6MT includes a six-speed manual gearbox.

Many optional features are also available. The Premium Package includes a moonroof, an upgraded Bose audio system, heated front seats with driver memory, a power tilt/telescoping steering wheel, an auto-dimming rearview mirror and Bluetooth connectivity. Go for the Technology Package to get adaptive cruise control, adaptive headlights and a rearview monitor. A hard drive-based navigation system with real-time traffic and MP3 music storage capability is available, as are satellite radio, a four-wheel steering system and real wood interior trim.

The G35 coupe is available in either base or manual transmission "6MT" trims. Both are equipped similarly to the base G35 sedan. In addition to a six-speed manual gearbox, the 6MT includes more power (293 hp vs. 275) and a sport-tuned suspension with 19-inch wheels. Option packages are generally similar to the sedan's but lack many of the new-for-'07 features.

A 3.5-liter V6 powers all 2007 Infiniti G35 models. In the sedans, it makes 306 hp and 268 pound-feet of torque. For the coupes, it makes 293 hp and 258 lb-ft of torque in the 6MT and 275 hp and 268 lb-ft in the automatic version. All but the 6MT trims have a five-speed automatic with manual control and rev-matching on downshifts. The 6MT trims have a six-speed manual. All versions are blindingly fast -- an automatic-equipped G35 Sport sedan we tested ran zero to 60 mph in 5.6 seconds and dispatched the quarter-mile in 13.9 seconds.

Antilock disc brakes with brake assist, front-seat side airbags, full-length curtain airbags, anti-whiplash front head restraints, traction control and stability control are standard on all G35s. On sedans, a tire-pressure monitor is also standard and a rearview monitor is optional.

The 2007 Infiniti G35 is quick, and even changing gears with the automatic is fun, thanks to quick response to the driver and rev-matching on downshifts. But this Infiniti also boasts finely balanced handling. Outright grip is remarkable and body motions are well-controlled. Although the ride quality is fine on the non-Sport suspension G35s, some folks may find the calibration too stiff on the latter cars. The brakes, on the other hand, are flawless. G35 sedans with the Sport trim get larger 13-inch rotors front and back, and they stop the car in impressively short distances. Our only dynamic complaint has to do with the G35 sedan's steering. Ratio and feedback are right on, but the vehicle-speed-sensitive assist needs some fine-tuning. When the vehicle speed is changing rapidly up and down -- as when running through a mountain road -- changes in the assist are too radical and too slow to come, which can give the steering an artificial, video-game quality.

A fairly long wheelbase of 112.2 inches makes for a spacious cabin for passengers whether they're up front or in back. However, the coupe's stylish, sloping roof line limits headroom for taller folks. Build quality is solid for the most part, if not up to the level of an Audi or BMW. The redesigned sedan boasts improvements in the cabin, such as the use of more soft-touch materials and real aluminum (or optional Rosewood) accents that enrich the interior considerably. Trunk capacity ranges from just 7.8 cubic feet in the coupe to 13.5 cubes in the sedan.