Stepping into a Lagonda transports you to another world

If you're one of the top members of Britain's America's Cup yachting team, you've probably been tooling around Newport, R.I., in an Aston Martin motorcar these past few weeks.

Morris L. Hallowell, head of the importing firm in the United States, lent three cars to the team: a Volante convertible; a V-8 coupe; and the creme de la creme, the Lagonda.

But if you're not a team member and you're not one of the handful of people who can afford to indulge themselves with this epitome of automotive excellence, British style, then you must be an auto writer who got his (or her) hands on a Lagonda for a test spin. Strictly business, you understand.m

(It was an Aston Martin that was used by Bond - James Bond, that is - in the early Agent-007 movies - the car with an arsenal on board. No, the production Aston, if you can call the cars that, don't perform the tricks that 007 could perform.)

''What kind of car is that, sir?'' the toll taker on Connecticut's Merritt Parkway asks, an unknowing look on his face.

''It's an Aston Martin Lagonda,'' I reply with some pride, even if short-lived (because it's not reallym mine).

''You look real sharp, sir,'' the toll taker responds. I drive off in the snappily designed, yellow-tone car, feeling like a millionaire.

The car I am driving is the 238th Lagonda built by Aston Martin Lagonda of Newport Pagnell, England, a small, prestigious company that turns out four cars a week, every last one of them built by hand.

Motorists buzz by, brake, and wait for the Lagonda - firmly priced at $150, 000 - to catch up. Expectedly, the car gets a lot of ogling on the highway. Heads turn and people smile, wave, or probably just dream. It's that kind of car.m

''It's another world,'' an admirer sums up.

Indeed, driving an Aston Martin motorcar is a visit to another world. Whether it's worth the trip - and the money - depends on the buyer.

The Lagonda, according to the car manual, is ''designed to combine sustained, high-speed driving with rapid acceleration and positive control. New owners are advised, therefore, that the response of the car to the controls calls for decisive handling. Until the owner has become thoroughly familiar with the car's high level of performance, it is respectfully suggested that the car is driven with extra care.''

With an overall length of 17 feet, 4 inches, and a wheelbase of 9 feet, 7 inches, the Lagonda is not a small car, by any means. Curb weight with a full tank of fuel is 4,622 pounds.

It is a combination of space-age technology and old-world craftsmanship with an all-aluminum body and engine. The bodywork is built by hand, a step at a time , and when finished, it all fits together with superb precision.

A total of some 2,000 man-hours go into the manufacture of an Aston Martin Lagonda, 900 man-hours for the body shell alone.

The instrument panel is quite unconventional and consists of warning lamps and digital displays, including heat-sensitive electronic controls to the right and left of the steering column. Some of the data are only given in metric measure, a source of irritation to some motorists. The car has a manual choke.

So I'm driving one of the most exclusive cars around, bar none. It was only a few months ago that the Lagonda got a go-ahead from the federal govenment for sale in the United States.

The engine, stamped beneath the ample hood - on a brass plate, mind you - with the number 3238, was built by Frank Matthews, one of four engine builders employed by the company. You can't say that about your Chevy, Ford, or Toyota!

But don't ask about the horsepower. Like Rolls-Royce, the company won't say. ''It's sufficient,'' says a smiling Mr. Hallowell.

The fuel tank holds 30 US gallons. At an average 10 miles to a gallon of gas, prepare to fill the tank often.

But if you have the money to buy the car, who cares? And then there is all that comfort! There are, for example, two air-conditioning systems in the car, one for the front and one for the rear.

Since 1912, the company has built 9,000 cars, with the US getting about 1,500 since 1960.

''We have files on all 1,500,'' Mr. Hallowell reports.

Don't look for an odometer inside the car. A trip meter, yes; but if you want to find out how far a Lagonda has gone, lift the bonnet - or hood - and look inside the engine compartment.

To appreciate an Aston Martin, you have to have a certain ''feel'' about the car. There is the tactical feel of the steering and suspension, but to reallym enjoy the car as it was meant to be enjoyed, it has to become a partm of the driver.

Indeed, the Lagonda isn't garish - that's for sure. It provides a fine ride, and the road control is superb. Perhaps it's simply ''British understatement,'' says one motorist who sat behind the wheel for a few miles.

Avon Turbo Steel radial tubeless 235/70 VR15 tires are standard on the Lagonda.

Yet despite the car's exclusivity, this doesn't mean there are no faults. The remote control for the right outside mirror, for instance, wouldn't work, and a pad on the accelerator pedal peeled away. Too, toward the end of my five-day test drive, the engine had a tendency to ''surge,'' or race, whenever I stopped.

And while not a fault perhaps, it's hard to see the dashboard readouts if you get bright sunlight through the back window. The cruise control, set at 55 m.p.h., picks up to 65 or 70 downhill, requiring frequent applications of the brake.

No matter, the speed control can be adjusted. The warranty is 24 months or 12 ,000 miles, and the company aims to do the job right.

One man bought a Volante and dropped by the import facility in Greenwich, Conn., to pick it up. While in the shop, he spied a Lagonda on a grease rack being ''prepped'' for a dealer. The buyer, who already had committed to the $110 ,000 automobile, told Mr. Hallowell that he ''just had to have that Lagonda.'' When he left town, he had bought two Aston Martin motorcars and left behind a quarter of a million dollars plus.

A prototype of the car was introduced at the London Automobile Show at Earl's Court in October 1976. At its Los Angeles introduction, 45 were sold, including three each to two Mideast sheikhs.

If you don't want the car, Aston Martin also sells a $10,500 motorcycle, hand-built at the rate of one a week in the workshops of Britain's Lord Hesketh.

The importer has a dozen dealerships in the United States, and Mr. Hallowell has his order book in hand.

The next move is up to you! What'll it be?