Looking back, Infiniti has always seemed to be searching for that finite demographic, that elusive middle of the road.

Reasonably priced sport sedan? Got it in the G35. Flagship, landmark cruiser? Drive it in the Q45.

But where was the gap-filler, the car big enough to lure existing lower-end Infiniti owners up into another level or keep a few sportier buyers in the same brand without jumping ship? With Infiniti, there always seemed to be a letter missing.

For 2003, dial M for middle ground - as in the newly unveiled M45 - and ask for Gloria.

Gloria?

Well, nearly something named Gloria.

Nicely positioned between the Q45, with which it shares many major drivetrain components, and the newly introduced G35 sport sedan, Infiniti's got a new look for a new year. Actually, it has had it all along, just not on these shores, just not with this name. Infiniti has offered a compromise for some time, a vehicle curiously called "Gloria." The only catch was that you had to go to Japan to drive her.

Finally settled in North America and renamed the M45, the collection is complete; the closet is full.

As the latest addition to a lineup of powerful front-engine, rear-wheel drive sedans, the M45 not only delivers a unique driving experience from its advanced 340-horsepower, 32-valve 4.5-liter DOHC V-8 engine and four-wheel independent suspension, Infiniti says it also offers a level of sophistication not found in similarly priced six-cylinder competitive models.

And the V-8 is key. There isn't much of a market yet for a niche-buster like this because there just aren't many cars priced in the $40s that offer all that gusto.

If they were trying to make a splash, consider the pool empty.

The M45 not only carries more beef, it rides in with just as much beauty. Just to make sure it had a fighting chance, Infiniti has dropped in many of the luxury items normally found in higher-end rides. That means "Sojourner" leather upholstery, speed-sensitive steering, anti-lock brakes, stability control and plenty of bird's-eye-maple trim.

Maybe M is actually for "mate" because much of what has been put into the M45 can be found in its cousin, the Q45.

The option list is lengthy and hefty in technology.

The M45 is the only car in its class to offer optional Intelligent Cruise Control, an automatic speed adjustment system that uses lasers to sense vehicles ahead and adjust speed to maintain a selected distance.

There's more, including a DVD-based navigation unit, a tire-pressure warning system, climate-controlled front seats, voice recognition, Bose premium digital audio system with seven speakers, dual-stage supplemental front air bags and front-seat side-impact and curtain side-impact supplemental air bags. With a medium-sized driver, there's even the option of reclining the rear seats by as much as 40 percent more than regular rear seats.

Combine all of that and suddenly the middle i s a marvelous place.

Inside, Infiniti says the interior of the M45 is all-new and plenty ritzy for the kind of demographic it's seeking. For some, it might be a little overwhelming. Working all the gauges won't require a degree from MIT, but it may require a good read of the manual.

Rear-seat room also gets a little cramped with five adults along for the ride. And don't expect to bring five sets of golf clubs - they won't fit in the trunk.

On the outside there are distinctive, sculpted exterior with high intensity discharge xenon headlights and rear taillights with clear reflectors.

Like the Q45, only one transmission is offered, an electronically controlled five-speed automatic with manual override. But there are many interesting packages to choose from, including the Comfort and Convenience, the Technology and two Premium packages.

As for driveability, the M45 rides in with a ringing endorsement. It attacks the twists in the road with attitude and doesn't roll too much in the corners. Stomping on the V-8 will give you all the gusto you could ask for in something that is not called a Mustang or an SUV.

It's brawny and brilliant, especially for a new entree.

Overall, the M45 pretty much as close to the middle of the road that Infiniti is going to get. In that way it may even attract Infiniti buyers looking to move up from an I35 or G35 or those looking for the best bang for the buck in this class.

Either way, it delivers.

Either way, Gloria has a new name for a whole new audience.

2003 INFINITI M45 - SPECS

High gear: With a muscular V-8 and plenty of luxury features, the M45 is a good dollar-to-feature leader, a breath of fresh air in an ultra-competitive segment.

Low gear: Rear seat room is a little cramped with everyone on board and trunk room can't take as much as some of the competition. Interior layout requires a good read of the manual to figure out.

Rating: 3.5

Vehicle type: Rear-wheel drive, front-engine, four-door, five-passenger sedan.

Key standard equipment: Five-speed shiftable automatic transmission rear wheel drive; 18-inch alloy rims with performance tires; front and rear ventilated disc brakes with four-wheel ABS; traction control; stability control; front side-mounted air bags; front and rear head air bags; remote anti-theft alarm system; dusk sensing headlamps; leather upholstery; 10-way power driver seat; rear heating ducts; remote power door locks, power windows, power mirrors; cruise control; power, tilt steering; dual zone climate controls; 225-watt Bose AM/FM cassette 6-CD stereo and multi-CD located in glove compartment.

Competition: Cadillac DeVille, Audi A6, Lincoln LS, Volvo S80

Engine: 340 horsepower, 4.5-liter DOHC, 32-valve V-8

Torque: 333 foot-lbs. @ 4,000 rpm

Wheelbase: 110.2 inches

Length: 197.2 inches

MPG rating: 17 mpg city/23 mpg highway

Manufactured: Japan

Warranty: Basic warranty is four years/60,000 miles; powertrain warranty is six years/70,000 miles; rust perforation warranty is seven years/unlimited miles; roadside warranty is four years/unlimited miles.

Base price: $42,300

Price as tested (includes options, destination and delivery charges): $42,845