"My name's Harley Earl." So says the nattily dressed man appearing in the new television advertisements for Buick cars. Buick, the ads proclaim, represents the "Spirit of American Style." Just who was Harley Earl? He's certainly not the actor in these commercials; the real Harley Earl died in 1969. But during his three decades at General Motors, Earl changed the shape of the American car.

Picture an antique car. Tall, boxy, and disjointed, the car of the early 1900s had parts that jutted out from the its body, as if they had been welded on: headlights, fenders, a luggage rack, running boards, a spare tire, and a bulky radiator grille. The windshield, split into two panels, stood stiff and upright. Passengers in the back seat rode high, directly above the rear axle, which meant a bumpy ride. The antique car seemed like the arthritic ancestor of today's sleek, speedy roadsters. But back then, whether a car worked well mattered more than whether it looked good; early automobile manufacturers were much more concerned with function than form. Their cars were notoriously unreliable, so engineering refinements had to take precedence over aesthetic appeal.

By the 1920s, automobile manufacturers had ironed out the major mechanical kinks in their product, and they grew interested in using a car's appearance to lure new customers. It was then that Harley Earl arrived on the scene. In 1926 General Motors hired Earl, a California native who had designed custom-made car bodies for movie stars, and soon put him in charge of GM's new Art and Color Division, which during the 1930s became known as its Styling Division. The name change was deliberate; Earl preferred the term "styling" and brought it in vogue.

The new term was just the beginning. Earl determined to change the appearance of the automobile. He wanted a car to look smooth, so he blended its conspicuous components--such as headlights and fenders--into the main body. In back, he eliminated the luggage rack and created a built-in trunk. In front, he concealed the radiator grille. Once, when toying with a car sketch, he rubbed his thumb over the running boards and erased them, then decided to remove them from real cars as well. The trend of Earl's work was to lengthen and lower car bodies, which streamlined cars and made them look speedier. To do this, he brought the passenger compartment down and cradled it between the front and rear axles, which gave passengers a smoother and more comfortable ride.

Earl also wrought revolutionary changes in the design process. Automakers used to glimpse new designs for their cars by hammering out metal sheets. Earl introduced modeling clay to make full-scale mock-ups of cars, molding the clay and then viewing changes; the process was easy and inexpensive. He unveiled the idea of a concept car, a futuristic prototype that allowed manufacturers to peer into the future of automobile design and gauge consumers' reactions and tastes. Earl's first concept car (called a "dream car" at the time) was the 1938 Buick Y-Job, which Earl himself drove. To look at the car today is to realize how far-sighted Earl was. A two-seat sports car that featured hidden headlights, power steering, flush door handles, and electric windows, the Y-Job looks more like a car from the 1950s than a Depression-era vehicle.

The post-World War II period brought about more Earl-inspired changes. Not all were good. Fascinated by jets and airplane designs, Earl decided to affix tail fins--which resembled fighter plane rudders--to Cadillacs in the late 1940s. The fishtails became standard on many cars in the 1950s, but symbolized automobile styling gone amok. Still, consumers took to them, and Earl's better innovations continued to find their way into the automobile, such as two-tone paint, the four-headlight system, and most notably, the one-piece, wrap-around windshield.

By the time Earl retired in 1958, his legacy was secure. He brought the word "styling" into Detroit's lexicon and made it a legitimate part of the car-making process. Ford and Chrysler established their own styling divisions, hiring many workers whom Earl had trained at GM. Styling showed that the car was more than just a functional vehicle of transport. It expressed art, tastes, even dreams of the future. "I dream automobiles," Earl once wrote. He probably never dreamed that, more than thirty years after his death, GM would use his name in advertisements. But why not? Today, style is a big selling point in cars. And the most influential automobile stylist in history was Harley Earl.