TRAVERSE CITY, MI -- General Motors Corp.'s Buick Motor Div. is embarking on a strategy to further distinguish LeSabre from the top-of-the-line Park Avenue/Ultra series as its rotund Roadmaster heads for oblivion when the '96 model year ends.

The results will become evident when the new models debut in January at the North American International Auto Show in Detroit. The '97 LeSabre, which goes on sale in January, is barely changed. Park Avenue and Ultra, however, are a tad bigger, feature all-new exterior and interior styling, and adopt an advanced version of the rigid body structure and chassis set-ups first introduced in the 1995 Riviera. They'll go on sale next fall.

LeSabre front and rear styling is tweaked, steel replaces plastic in the front fenders, and there are new front and rear lamps and a new hood. But otherwise Buick takes a conservative approach to protect LeSabre's position as the best-selling U.S. full-size car.

But don't get the idea LeSabre lacks guts. Under the hood is a very respectable 3800 Series 11 V-6 that pumps out V-8-like 205 hp, yet provides 19/30 mpg (12.4 to 7.8L/100 km) in city/highway driving.

Buick saves the most dramatic changes for Park Avenue and Ultra, creating a new look that suggests more luxury, more power and more substance than the '96 model.

Patrick J. Harrison, marketing line manager for Park Avenue/Ultra and LeSabre, says Buick's strategy is to also differentiate Park Avenue from Ultra. Park Avenue buyers are expected to be slightly older (45 to 65) with median annual incomes of around $65,000. Ultra aims for the 40-60 age group with incomes averaging $75,000.

Except for badging (Park Avenue has a stand-up hood ornament, for example, while Ultra's badge is embedded on top of the grille), it remains difficult to distinguish between the two models. Ultra basically carries more standard equipment, most importantly the supercharged version of the Series II V-6 producing a hefty 240 hp, which is optional on Park Avenue.

Both cars get a new 4T65E Turbo-Hydramatic transaxle, seat-mounted safety belts, power headrests, magnetic variable-assist steering with six settings and radio antennas embedded in the rear windows. There's also a new door-multiplexing system that reduces bulky wiring by 75%, improving packaging and reliability.

Traction control and a new rain-sensing windshield wiper system are optional on Park Avenue, standard on Ultra.

By utilizing Riviera's 25-Hz "greenhouse" steel structure, Buick Exterior Styling Studio No. 1 Chief Designer William L. Porter created a new appearance that artfully blends soft aero cues with distinct, sharp creases. One chief element of the new design is what he calls a "chamfer plane," or continous surface line, that "runs from the headlamps, along the top of the front fenders, through the doors and into the rear fenders." The result is a clean, elegant look.

The cars incorporate numerous other refinements. The fixed front quarter windows, still used on LeSabre, have been eliminated to improve visibility. Side mirrors are 75% larger, also to enhance visibility.

Inside, Buick has dropped the arguably archaic Park Avenue/ Ultra instrument panel for an all-new design with larger graphics, and radio and air conditioning controls are mounted higher for easier access.

In an explosive debut in New York City, BMW reveals its new Z3 roadster to the press, complete with Q, the mythical James Bond's gadgety weapons provider presiding and BMW chairman Heimut Panke looking on.

The two-seater, produced at a new Spartanburg, SC, plant, is designed for the purist who wants to experience a true roadster, Mr. Panke says.

Sales begin in Europe first, and the Z3 will be exported to more than 100 markets, Mr. Panke says. It will go on sale in the U.S. in the first quarter of 1996 with a $28,750 price tag, in time for the peak spring coupe season.

U.S. dealers will get display models before that and will be able to accept orders before the vehicle goes on sale. Some 3,600 orders already have been accepted by U.S. dealers.

The Z3 is the first roadster BMW has sold in the U.S. since 1959 when it offered the 507 model. The new roadster has an all-steel body mounted on a chassis that is 10 ins. (25 cm) shorter than 3-series cars. It is only 50.7 ins. (129 cm) high and weighs 2,690 lbs. (1,220 kg); that's 400 lbs. (180 kg) heavier than the Mazda Miata. The Z3 is powered by an all-new 1.9L 4-cyl. 16-valve engine that is the successor to the 1.8L in present 318 models, which will also get the new engine in 1996.

The new engine is built with a cast-iron block and a redesigned aluminum cylinder head. The 1.9L has more displacement, with bore increased from 84 to 85 mm and stroke from 81 to 83.5 nim.

BMW says the new engine has more torque and better low- to mid-range response. The engine produces 138 hp at 6,000 rpm and torque is increased from 129 to 133 lb-ft. (174 to 180 Nm). Maximum power peaks at 4,300 ipm instead of 4,500 rpm in the previous generation engine. However, acceleration from 0-60 (97 kmh) mph is only claimed to be 9.1 seconds with manual transmission. With a four-speed automatic, acceleration fime is 9.7 seconds -- not exactly screeching performance for a sports model. The soft top is manually operated, and there is a removable hard top planned for introduction on 1997 models. U.S. buyers will find two cupholders, and the trunk can hold enough luggage for two on a weekend trip. A spacesaver spare drops down from its storage space below the trunk. Herb Shuldiner