Just when you thought the station wagon was dead, General Motors bringsit back to life.

That`s ``life`` as in the first new sheetmetal on the machine since yourteenage son or daughter was born.

The slabsided wagon of the `70s and `80s has been replaced by one withrounded corners and edges, the so-called aero look that not only means apleasant new appearance, but a slight boost in fuel economy as well from itsability to slice through the wind rather than be buffeted by it.

We test drove the Chevy Caprice and Buick Roadmaster Estate wagons, twoof the trio of new wagons from GM for 1991 that also includes the Olds Custom Cruiser. We`ll review that one at a later date.

Both offer distinctive, eye-catching styling in sharp contrast to theblock of metal that had been running around the streets since the late `70s.

What made wagons appealing in the `70s is still offered for the `90s, a115.9-inch wheelbase and 217.5-inch length to provide the room for three sets of seats and eight-passenger carrying capacity.

The rear tailgate has a popup window for easy storage of small packages,or you pull one of two release levers to swing the gate open sideways to letthe kids in or swing it down to pile the groceries in. There`s even room forthe dog to roam.

The third seat holds the little kids facing rearward so that the noisetravels away from the driver and front-seat occupant.

The wagons are big enough to tow a boat, though when you look back alongthe car in the rear-view mirror from the driver`s seat, it looks like youalready are in a boat.

What made station wagons less than appealing in the `70s also is stillpresent for the `90s.

That long wheelbase and length means when you pull into the supermarketthe tailend sticks out past the normal sedans and coupes. Those new to bigwagons will find slipping into the typical parking space is like getting into last year`s suit or dress.

Even more fun awaits you when you decide to leave the space. Here inDetroit, our first venture with the Chevy wagon meant leaving a parking garagepacked with cars filling the angular lines. The size of the Caprice meantbacking up, pulling forward, turning the wheel and backing up again, pullingforward . . . you get the picture.

Neither the Caprice nor the Roadmaster was as nimble as a Mazda Miata inthe everyday task of parking. We didn`t attempt parallel parking between twovehicles, which was a cumbersome chore when the wagon had flat sides and rear end and can`t be any easier now that its rounded.

The other problem with wagons was fuel economy. This pair is rated at 16m.p.g. city/25 m.p.g. highway with their 5-liter, 170-horsepower V-8 engines. A larger 5.7-liter V-8 won`t be offered because it would face a gas-guzzlertax.

With eight-passenger capacity, wagons are very fuel-efficient vehicles at 16/25-providing you carry eight people and not just one.

C ompared with the slab-sided boxes, the new wagons are more limber andeasier to maneuver, though 217.5 inches of length will never make them easy topark. Gas-charged shocks make for a smooth ride in both. But with a wagon, anda full-size wagon at that, you quickly learn you must adjust to the extrafootage, such as when backing up or when pulling in and out of the passinglane.

The 5-liter V-8 is slightly underpowered, which you feel when starting up and especially when climbing inclines. But again, that`s better than a guzzlertax. The typical wagon owner won`t be as concerned in speeding away from astop as in carting seven screaming kids and a barking dog through the suburbs,or pulling the boat or trailer along the interstate, along with the sevenscreaming kids and the barking dog.

The Buick Roadmaster carries a 100 m.p.h. speedometer, the Caprice an 85m.p.h. speedometer. Chevy will soon change its reading. The low 85 unitdistorts common perceptions. When you`re traveling at 65 m.p.h. on theinterstate, the needle is just about out of room to move much further. Seeing the needle way off to the right makes you feel as if you`re traveling fasterthan you are.

The Roadmaster and Caprice offer two items not available on previous GMwagons-driver-side airbags and antilock brakes, the latter a must feature for a vehicle entrusted to hauling kids, their friends or teammates. The airbagand ABS are standard.

The Roadmaster features a tinted glass Vista roof as standard equipment;the Caprice doesn`t offer it even as an option. The Vista roof over the secondseat allows passengers to catch the scenery overhead and makes for an airyfeeling inside the compartment. But even with the roof in the Roadmaster andwithout it in the Caprice, both wagons shortchange second-seat occupants when it comes to thigh support. Maybe Chevy and Buick figured only kids would roam in that second seat.

Other standard equipment in the Roadmaster includes tinted windshield,manual third-seat vent windows, bodycolored dual outside mirrors (right sidemanual is a dumb touch, making the driver reach over), tailgate releaseswitch, visor vanity mirrors, power windows with the driver`s as an ``express down,`` rear cargo net, luggage rack, air conditioning, power brakes andsteering, hood ornament, bodyside moldings, AM-FM stereo with clock, tiltwheel, steel belted radial whitewalls, and rear window wiper/washer. Woodgrainvinyl applique is standard but you can delete it for credit.

The Roadmaster wagon starts at $21,445.

There`s less standard equipment in the Caprice-delete the power windows,bodycolored mirrors, visor vanity mirrors, tilt wheel, whitewall tires andtinted glass Vista roof found on the Roadmaster Estate wagon.

But then the Caprice starts at $17,875.

Would we want to pack the crew into a stylish new Chevy or Buick wagon or a mini-van for a trip to Wisconsin or Michigan? The van. The van also carries a crowd, yet is far easier to park and maneuver than the block-long wagon. Anda van gets far better mileage, even if it does so with a smaller engine andeven if front-wheel drive severely limits or rules out towing. And sliding theside door open is a handier way to load and unload the gang than fooling with four doors and a liftgate.

Last week in Dearborn, Ford Division General Manager Tom Wagner said thefull-size, rear-drive Crown Victoria and Mercury Grand Marquis wagons will be dropped after the 1991 model run. He said the smaller, but more fuel-efficientTaurus wagon and larger, but more fuel-efficient Aerostar van would pick upthe slack. We think he`s right.