Imagine a major aircraft company such as Boeing deciding to build a better car than BMW, Porsche or Mercedes-Benz.

That's exactly what England's Bristol Aeroplane Co. decided to do in 1945 after World War II, when companies around the world began looking for something to do when military contracts began running out. Some airplane producers felt that cars seemed like a good substitute because materials and construction techniques were rather similar in that era.

For instance, Convair in San Diego built some prototype cars and Beechcraft presented the Plainsman auto, but nothing came of their efforts.

Bristol Aeroplane was one of England's largest airplane producers and was smarter than most because it began slowly with automaking as a high-quality sideline operation, partly with redeveloped pre-war BMW designs.

Bristol Cars Co. now is a very private British outfit that builds autos to order for wealthy folks, including celebrities. (British actor Peter Sellers was a longtime Bristol customer.) Bristol doesn't advertise or release production figures and sells cars from a quiet, wealthy London location. It still builds autos using aluminum-intensive construction techniques it utilized when making airplanes. One twin-turbocharged Bristol has 1,012 horsepower and can top 200 mph. Prices aren't listed, although one of the last Bristol models sold for $400,000 at 2006 exchange rates.

Bristol got the services of top BMW auto designer Fritz Fiedler, along with blueprints of late 1930s BMW autos to work with, thanks to H.J. Addington, a key figure in the new Bristol auto operation. A friend of Fiedler's, Addington headed the British Frazer-Nash auto company that was the pre-war distributor of Germany's BMWs to England.

BMW was devastated by the war and Bristol initially used BMW designs purloined as "war reparations" and redeveloped with Fiedler's help. The first Bristol was presented at the 1947 Geneva Auto Show as the Type 400. It was pretty much a pre-war BMW 327 four-seat coupe with a modified efficient engine with hemispherical ("hemi") combustion chambers. But it was still England's best car because its basic 1930s BMW design was way ahead of its time.

The 400 was heavy and no styling standout, although it looked aerodynamic, coming from an aircraft firm. It had excellent handling and precision construction, besides the finest materials. Bristol had no intention of competing with large automakers, or even Rolls-Royce. Rather, it began patiently making a limited number of cars for wealthy, discerning, mostly middle-aged folks. The 400 had a slim BMW-like "twin-kidney" grille.

Bristol found 700 buyers for the 400 through 1949, when that luxurious, adequately fast model was replaced by the 401, which had a little extra horsepower that helped it hit 100 mph with its more streamlined styling "such as might be expected from an aircraft builder intent on showing his skill," said a British historian. Some 20 years after the 401's demise, just four modern cars were found to be more aerodynamic.

The 401 body was inspired by Italy's Touring, with its elegant teardrop tail and smooth contours, and had Touring's superlight construction, with aluminum body panels attached to a strong, multi-tube frame. The 401, which still had a BMW-style grille, was accompanied by a derivative, well-detailed 402 convertible with a soft top that folded completely away.

The 401/402 was produced from 1949 to 1953 and had slightly lower production than the 400, with 650 coupes and just 24 convertibles built.

Bristol was perfectly satisfied with sales and saw no need for a radically different 1953-55 403 model for its low-volume, high-price market. The 403 coupe (no convertible was offered) looked much the same as the 401 and retained a slim BMW-style grille because it was essentially an aerodynamic BMW with exquisite workmanship and a stiff price. However, major mechanical changes were made to the driveline, suspension, brakes and even the heater. Horsepower was increased to 100 and the engine worked with an improved four-speed manual transmission. The short-lived 403 registered sales of 300 units.

By the early 1950s, BMW was getting back on its feet and began making cars again with its twin-kidney grille, so Bristol introduced an all-new compact two-seat 404 fastback coupe with a 110-mph top speed, nicknamed the "Businessman's Express." This Bristol had no grille -- just a large, square hole often filled with huge Lucas Flamethrower driving lights in the center. In profile, the grille resembled the leading-edge air intakes of Bristol's Brabazon airliner.

The 1953-56's 404's styling was smoother and more modern than the 403's and the car had tiny tailfins. It used a short-wheelbase version of the regular solid Bristol chassis (96 inches vs. 114), and its BMW-inspired six-cylinder 105-horsepower engine had a 125-horsepower option that made the 404 the fastest Bristol yet. The car weighed only 2,265 pounds for solid acceleration and handling. Brakes were improved to cope with its higher speeds.

The 404's body, a well-engineered mixture of steel and light-alloy panels over a wood frame, introduced a housing in the left front fender for the spare tire -- a feature that became a Bristol hallmark. A right-hand hatch concealed the battery and electrical parts.

Few drove -- or even saw -- the 404 because it was terribly costly at $9,946 in England, which was still suffering from effects of the war. Besides, most Bristol customers wanted more than two seats. The car was almost impossible to sell, and only 40 thus were built.

However, just a year after the 404 appeared, Bristol unveiled its first four-door sedan, called the 405. It had essentially the standard-wheelbase 403 chassis with the 105-horsepower 404 engine, although a 125 horsepower version also was available. The sporty 1954-58 405 shared front styling with the racy 404, but its larger body had a notchback style with nicely rounded lines that made it look more aerodynamic than the 403 it replaced. It was roomier and a larger glass area made the interior airier. The body again mixed steel and aluminum panels over a wood framework. The 405 also had standard overdrive for more relaxed high-speed cruising.

The 405 sold well, considering Bristol's small, exclusive car operation. A total of 340 were sold, including 46 rare two-door convertibles with coachwork by Abbotts of Farnham.

By 1961, Bristol was making faster, slicker cars with potent Canadian-made Chrysler V-8s, built to Bristol specifications.

Bristol owners in America who try to impress others by saying they own a Bristol likely encounter blank stares. In England, though, it's an entirely different story.