Fender skirts, known in Australia and the United Kingdom as spats, are pieces of bodywork on the fender that cover the upper portions of the tires of an automobile. They are usually used on rear wheels only, but some models have them on all four wheels. Functions Fender skirts are implemented for both aesthetic and aerodynamic reasons. Rather than air flowing into and being trapped in the rear wheel well, it flows smoothly over the bodywork. They are generally detachable to allow for tire changes and installation of snow chains. Automakers have also experimented with integral front wheel fender skirts, as on the 1949–1954 Nash "Airflyte" models and the compact 1950–1954 Nash Rambler, but with success limited by the fact that the front wheels must pivot for steering, extending out from the side of the vehicle slightly. The 1955 Ford Thunderbird introduced rear "fender shields" as a type of fender skirts with an edge molding and a gravel shield. In GM parts accessories books, fender skirts are known as fender shields. History First described as "pants", they were used for the streamlining effect by Frank Lockhart on a 1928 Stutz land speed record attempt car. Factory production of fender skirts began with the 1932 Graham-Paige. Aesthetically streamlined designs were copied to mass-produced models. The innovations introduced by Amos Northup, such as the V'd radiators, fender skirts, and sloping beaver-tails, became common after 1933. The fender skirt the "stylish cars in the past, making them look like glorious floating boats, classy and elegant." Fender skirts remained a feature for some time longer on a few cars, particularly large American luxury cars. However, by the 1970s, fender skirts began to disappear from mass-market automobiles. Fender skirts were often paired with whitewall tires. The extent of the skirt also varied; before the 1950s it was common for all but the very bottom of the rear tire to be covered, while by the 1960s fender skirts only covered some of the top of the tire and were largely absent on cars other than top-line models. For example, starting in the mid-1960s until 1976, the Chevrolet Caprice, Oldsmobile 98, Buick Electra, Pontiac Bonneville, as well as the Cadillac Fleetwood, DeVille, and Calais models used fender skirts. The Cadillac Eldorado models featured fender skirts from 1971 thru 1974. Starting in 1977 only the Pontiac Bonneville retained the use of fender skirts on General Motors' downsized cars.