Cadillac DeVille Presidential Limousine
The presidential state car is the official state car used by the President of the United States. A variety of vehicles have both officially and unofficially been acknowledged as the presidential vehicle. Since the late 1930s, the U.S. government has specially commissioned vehicles for presidential use, often specifying advanced communications equipment, special convenience features, armor plating, and defense countermeasures.
American cars are traditionally chosen for the role. The most recent vehicle to be customized as the presidential car is a GMC Topkick-based, Cadillac-badged limousine often referred to as Cadillac One and occasionally as Limo One (a reference to the U.S. presidential aircraft, Air Force One) or as The Beast.
Source: Wikipedia, 2011