Nissan's four-door sedan for the mid-size class projects aggressive styling and packs aboard a big V6 engine. Exterior designs look crisp and clean, but also aggressive and powerful with taut skin stretched over muscular shoulders and flat side panels interrupted by bulging fenders.

Altima appears in four trims described by the size of two engine options. An entry model and two upgraded issues carry a dual-cam 2.5-liter in-line-four plant and line up as the Altima 2.5, mid-grade 2.5 S and deluxe 2.5 SL. Top Altima 3.5 SE packs Nissan's 3.5-liter V6 good for 245 hp now. A five-speed manual or four-speed automatic works with either engine.

Several packages of gear go to SE, such as the 3.5 SE Sport Package Plus with sunroof, tail spoiler, xenon headlamps and Bose audio, or the Premium Leather Package with leather draping the cockpit. And a fresh exterior color choice for Altima emerges under the label of Smoke.

The fifth generation of Nissan's compact-class Sentra sedan gains styling enhancements for 2004 plus more convenience features. Headlamps and rear combination lamps have been reworked with smooth fascia added front and rear plus a carved hood and unique grille.

Inside the generous cabin, two race-style bucket seats stand up front with a split-and-fold rear bench. Cloth bucket seats are standard on all models in three new colors, depending on model and trim. Added interior gear ranges from Rockford Fosgate audio kits to a trip computer, optional sunroof and remote keyless entry system.

Models change nomenclature for 2004 with Sentra 1.8 replacing a base XE, Sentra GXE becoming the 1.8 S and the 2.5 LE changing to 2.5 S. Sentra 1.8 and 1.8 S draw from a dual-cam 1.8-liter four-cylinder engine racked to 126 hp with five-speed manual or optional four-speed automatic transmission. The 2.5 S stocks a 2.5-liter four-pack scored to 165 hp and linked to an automatic four-speed. Sport-tuned SE-R and racy SE-R Spec V Sentras return for 2004 with more equipment.

A special front fascia, styled after Nissan's exotic and powerful Skyline GTR sports sedan, adds a crisp mesh grille and round foglamps. Body-colored sills stretch toward the pavement along each side, while at the tail a winged spoiler flies off the trunk's flat deck.

Power for SE-R Sentras is the twin-cam 2.5-liter four that hits 175 hp for the Spec V performance edition. Spec V also has serious performance hardware, including a six-speed manual shifter, limited-slip differential, four-wheel disc brakes and tighter suspension tuning.

A Brembo Brake Package for high performance appears on the option list for SE-R Spec V now with gold-painted Brembo four-piston front calipers, 12-inch Brembo vented front discs and 10.9-inch rear discs.

Nissan's slinky two-door coupe with hatchback styling and sport-tuned hardware carries the engine up front with all power directed to big back wheels in classic pose with even distribution of the weight on front and rear wheels.

It looks so lean and mean, the exaggerated prow fixed with huge projector-type headlamps, fenders bulging to cover the oversized rubber rollers, a broad windshield cocked back at an extreme angle and the low roofline tapering past a hatchback window to the curt tail scored by lamps drawn forward on corners in twin triangular streaks of red.

For go-power, Z stocks a 3.5-liter V6 churning with 287 hp when teamed with a six-speed manual transmission. So many variations in trim mean custom selections. The base edition - 350Z 6MT - contains a six-speed manual transmission and 17-inch wheels with power controls for windows and door locks and mirrors, a remote keyless entry device and vehicle security system, plus automatic climate controls and a 160-watt audio kit.

Enthusiast 6MT adds xenon headlamps, aluminum foot pedals and cruise control, a viscous limited-slip rear differential plus TCS. The five-speed automatic transmission makes it the Enthusiast 5AT. A 350Z Performance 6MT model with manual gearbox moves up to 18-inch wheels and tires with a tire-pressure monitor and vehicle dynamic control (VDC) anti-skid equipment.

Z's Touring 5AT with automatic shifter has luxury gear like leather upholstery and power seats with heat elements plus a 240-watt Bose stereo and six-disc CD deck. Touring 6MT with the six-speed manual goes further with aluminum pedals, VDC and 18-inch rollers.

Ultimate 350Z Track 6MT gets light-weight alloy wheels and a tire-pressure monitor, vented Brembo brakes, xenon headlamps, spoilers front and rear, aluminum pedals in the cockpit and the VDC. The optional navigation system for the Z dashboard has a power-motivated face plate now, while the latest body color for Z is called Liquid Aluminum.

The hatchback Z-car drops its top to become a new convertible roadster variation for 2004. It has seats for two in a cozy cockpit with the 350Z V6 powertrain and a power-operated soft top set with a glass rear window.

A performance-oriented driver's seat in the roadster uses a firm base cushion with cutouts under both thighs to facilitate pedal operation. Driver's seatback shows sculpted wing bolsters to pin the torso to the seat during hard cornering maneuvers. Burnt Orange ventilated net-style seats with woven cloth center insert are available along with a built-in seat heater.

For storage, a lockable luggage box has been added on the floor of the cabin, and the trunk has about four cubic feet of room. The powertrain comes directly off the 350Z hatchback for a 3.5-liter V6 rated at 287 hp with six-speed close-ratio manual transmission or available five-speed automatic.

Trims are labeled 350Z Roadster Enthusiast Model and 350Z Roadster Touring Model. Standard gear for the former ranges from the power-operated drop-top to power seats, a wind deflector, 17-inch alloy wheels, xenon headlights, the automatic or manual transmission and an automatic climate system. The latter also stocks leather seats with heat element, heated exterior mirrors and Bose audio with six-disc CD changer.