The Rolls-Royce Phantom IV is a British automobile produced by Rolls-Royce. Only eighteen were made between 1950 and 1956, sold only to buyers whom Rolls-Royce considered worthy of the distinction: the British royal family and heads of state. Sixteen are known to still exist in museums as well as in public and private collections. Characteristics Rolls-Royce broke with their earlier decision to cease production of the series of "big" Rolls-Royce Phantoms after the end of World War II. The Phantom IV chassis differed from those of the shorter, production post-War models, the Silver Wraith and the Bentley Mark VI; apart from a larger size and an engine with increased capacity and power, they have an additional cross-member at the centre of the cruciform bracing and 10-stud road wheel mountings. The engine was a derivative of the 8-cylinder rationalized B range of petrol engines (formed by four, six and straight eight). Specifically it was a refined version of a B80, the last three of a B81, both used in military and commercial vehicles. The IV is the only Rolls-Royce motorcar to be fitted with a straight-8 engine, which was powerful but could also run long distances at a very low speed, an important feature for ceremonial and parade cars. All examples of this exclusive series were bodied by independent coachbuilders, and most of their bonnets surmounted by the kneeling version of the Spirit of Ecstasy, which had been unveiled in 1934 and used in various other models. History In July 1938, Rolls-Royce had to publish in the motoring press an announcement denying that the Phantom III fabrication would be interrupted. The following was published on 19 July 1938 in the British magazine The Motor: However, a project had been initiated in 1937 to rein in the manufacturing costs of the Rolls-Royce and Bentley (acquired by Rolls-Royce in 1931) motor car chassis. This involved the development of a Rationalized Range of cars that shared as many common components of the chassis as possible. As implementation of this rationalization plan, several prototypes were made. One of these, chassis 30-G-VII, was fitted with a large Park Ward seven-seater limousine body and was called Silver Wraith 80, then Silver Phantom, though it soon became known as Big Bertha. This was the genesis of the Phantom IV. Likewise, in 1939 and before the starting of hostilities, another straight-eight powered experimental automobile tested during and after World