In automotive engineering, a grille covers an opening in the body of a vehicle to allow air to enter or exit. Most vehicles feature a grille at the front of the vehicle to protect the radiator and engine. Merriam-Webster describes grilles as "a grating forming a barrier or screen; especially: an ornamental one at the front end of an automobile." The word 'grille' is commonly misspelled as 'grill' which instead refers to the cooking method. Other common grille locations include below the front bumper, in front of the wheels (to cool the brakes), in the cowl for cabin ventilation, or on the rear deck lid (in rear engine vehicles). Grilles evolved from previously installed gravel shields that were designed to protect exposed radiators typically used on cars until the early 1930s. Design The front fascia of a motor vehicle has an important role in attracting buyers. The principal function of the grille is to admit cooling air to the car's radiator. However, the look of the vehicle "matters a great deal more than whether the design features actually serve any function." As one of the main visual components on the front of vehicles, "an inspired grille design makes a car attractive and shapes its identity by tying it to the carmaker's history and reputation." Currently, big grilles are primarily cosmetic. The grille is often a distinctive styling element, and many marques use it as their primary brand identifier. For example, Jeep has trademarked its seven-bar grille style. Rolls-Royce is known for arranging its grille bars by hand to ensure that they appear perfectly vertical. Other makers known for their grille styling include Bugatti's horse-collar, BMW's split kidney, Rover's chrome "teeth", Mitsubishi's forward swept, fighter aircraft-style grilles for their cars 2008 Lancer and Lancer Evo X, Dodge's cross bar, Alfa Romeo's six-bar shield, Volvo's slash bar, Nissan's trapezoid shaped chrome surround, Mazda's rotary engine shape, Audi's relatively new, so-called single-frame grille, Pontiac's split horizontal grille and an egg-crate grille on late-generation Plymouths, and Lexus's spindle-shaped grille. The unusual 1971 Plymouth Barracuda grille is known as a cheesegrater. Ford's three-bar grille, introduced on the 2006 Fusion, has become distinctive as well. Porsche, a long-time manufacturer of air-cooled cars, continues to minimize the prominence of a "grille" on the marque's modern water-cooled vehicles in keeping with that heritage. The contrary styling pattern also occurs. Starting from the late 1930s, Cadillac would alternate its