Most car manufacturers are satisfied with annual model changes thatare a molding snip here, a bumper tuck there. When BMW introduces avehicle, it is a transition to a new epoch after many years of thought.

That makes the new 325i an elegant, fundamental shocker of summer.

The 1992 car has been freed of the flat planes, slab sides, blunt endsand somewhat boring three-box design that has been the hallmark ofentry-level Bimmers for more than a decade.

The new windshield and rear window finally show more slope than theaverage forehead. The front end is raked for the firsttime. Even BMW'sclassic kidney grille has evolved into vents that are more rectangularthan renal.

Yesterday's 325 was styled as a typical four-passenger sports sedan ofthe '80s: square, spare,light, flighty and even a little delicate.

Today's 325 follows in the tire prints of BMW's new 5- and 7-seriesgrand touring cars for the '90s: longer, heavier, wider and squatter,with the lookof serious performance.

The wheelbase has been lengthened by five inches, with the frontwheels moved forward to create a drastically reduced overhang. The backend has been shortened, shoved inand heightened to form the thick end ofa wedge profile. Pinched side sills and a slotted front air dam give thecar a lower stance with the European flair of Mercedes and the Alfa-Romeo164.

Inshort, it is an enormously adult Bimmer.

The only jarring note is the flat, clear plastic covers over theheadlights. When positioned alongside curved, molded and amber lenses forthe turn signals, the headlight lids come off as aerodynamicafterthought.

Under the car's solidly handsome looks, there's a new engine borrowedfrom the 525i: a 24-valve, inline-six producing 189 horsepower.That is12% more power than last year's car with a corresponding improvement inlow-end performance.

BMW has always built cars that were as much of their moment as theBeach Boys, sideburns and tank watches. But with Elvis dead, quicheappearing on cafeteria menus and yuppies an estranged species, BMWcontinues to transcend fads with a permanence built upon thoroughness ofworkmanship and technology.

Now the German company is storming ahead of its time with the 325i,which surely qualifies as the world's first production Green Car:

* Buyers may order a nonsmoking version with front and rear ashtraysreplaced by small storage boxes. The cigarette lighter is removed, butits socket and wiring remain to power portable phones, radar detectorsand blenders for instant freeway breakfasts.

* The intake manifold is cast from fiberglass-reinforced polyamidwhich, along with other plastic parts of the car, is fully recyclable.Some of those plastic parts already have been manufactured from recycledmaterials.

* Standard on the 325i is an electrostatic microfilter attached to theclimate-control system. It removes pollen, plant dust and even somebacteria from air entering the car.

Then there is BMW's knack for separating mechanical gimmicks fromtechnological assets and establishing safety features that likely willstill be around in 10 years.

* Crash research has shown that doors commonly jam on impact anddangerously deny egress to occupants. So the 325i comes with a crashsensor that unlocks the doors in an accident and activates emergencyflashers and interior lights.

* The restraint harness--complemented by a driver's-side air bag, witha passenger's pillow on the way--is fitted with an automatic tensioningsystem that, under collisionforce, snugs up lap and shoulder belts morethan two inches.

* Energy-absorbing front and rear bumpers are connected to the body ofthe car by disposable cylinders. These inexpensive tubes soakupcollisions up to 9 m.p.h. before damage occurs to more expensivestructures.

Internally, the new 325i is slightly roomier than earliermodels--particularly in rear-seat legroom--b ecause of itsstretch dwheelbase.

There is a small increase in trunk space, although the welcomeaddition here is a sill somewhere around the loader's ankles. On theother hand, the lid rises tall and requires a long reach with some heftyslamming to latch easily.

The interior is something of a disappointment. This 325i seems to havelost much of the classic design and superior materials that add tothecachet of the blue-and-white roundel.

Optional leather seats on the test car were soft, supportive andprobably worth an extra $1,100. But dashboard plastics and fabric liningshinted heavily at mass production and low bids, which is simply not thefeeling one expects from a $30,000 motor car.

In truth, the lines framing the analog instrument cluster and centerconsole rely heavilyon curves and swoops to encapsulate the car'soccupants. Such design is reminiscent of Asia and the very last influenceone wants to find in a thoroughbred German automobile. The interior doorlatchesare too small, mounted too high and set too far to the rear ofthe door for easy opening. And we would have liked a remote release forthe trunk.

Yet there is nothing to dilute the performance of the 325i. Ifanything, BMW has improved its longstanding reputation for versatility,combining passenger hauling with the pure handling of a sports car.

The new 2.5-liter engine is served wellby all those valves anddouble-overhead cams. It whispers during peaceful cruising, snoresmagnificently when asked to do exhilarating things and, with a top speedin excess of 140 m.p.h., is certainly much lustier than the averagedriver's talents.

Thanks to a 60% increase in body stiffness and a rear-axle setupadapted from BMW's vaunted Z-1 sports car (available only in Europe), the325i handles flat and sure-footed.

When the car's weight begins to shift during hard lane changes orheavy braking, the resultant tendency to lurch and roll is fully tamed bythe suspension. The accuracy and feelof steering and straight-linestability is preserved through all but the most excessive maneuvers.

Older 325s were more inclined to get loose in the rear end whenpowered hard throughturns. That tendency to over-steer remains with thenew car. But it is harder to induce, escalates only gently and is easilycorrected.

And unlike cars with lesser suspensions, the 325i performsthis fullrange of settling movements without the penalties of harsh springing orany loss of ride comfort.

Add 15-inch wheels, meatier tires and bigger disc brakes coupled to ananti-lock system, and only the young and intemperate should get intotrouble in this car.

It's only serious deficiency is the one blemish that has hauntedBimmers since birth: The final cost of this ultimate driving machine.

Ten years ago it wasn't such an issue. BMW had authored the brochureon high-powered four-doors that could outrun anything in their class.

Now there are several contenders. The five-cylinder Acura Vigor, allwood trim and elbow-deep luxury, is one. The new V-6 Mitsubishi DiamanteLS putting out 200 horsepower is another.

True, neither of these contenders has the souland set of the Bimmer.But for $6,000 less, and if valet parking vanities be the onlyconsideration, they beg a lot of examination.

1992 BMW 325i

The Good Styling forthe decade ahead. Flat, sure-footed, performance handling. Environmentally correct. Safety-oriented.

The Bad Interior moving to the generic. Still pricey after all these years.

The Ugly Headlights with contact lenses.

1992 BMW 325i

Cost Base: $27,990 As tested, $31,560 (including automatic transmission, leatherupholstery, heated seats, metallic paint and other options. Driver's-sideair bag, anti-lock brakes, dual climate control, power seats allstandard.)

Engine 2.5 liters, 24-valves, inline six cylind ers and double-overhead cams eveloping 189 horsepower.

Type Rear-wheel drive, five-passenger, four-door high-performance sedan.

Performance 0-60 m.p.h., as tested with automatic, 9.4 seconds. Top speed, manufacturer's estimate, 140 m.p.h. Gas consumption, EPA city-highway, with automatic, 18-25 m.p.g.

Curb Weight3,021 pounds.