The Rolls-Royce Silver Cloud was the core model

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

 of the Rolls-Royce Motor Cars

Rolls-Royce Limited

Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....

 range from April 1955 until March 1966. It replaced the Silver Dawn

Rolls-Royce Silver Dawn

The Rolls-Royce Silver Dawn is a car that was produced by Rolls-Royce at their Crewe works between 1949 and 1955. It was the first Rolls-Royce car to be offered with a factory built body which it shared, along with its chassis, with the Bentley Mark VI until 1952 and then the Bentley R Type until...

 and was, in turn, replaced by the Silver Shadow

Rolls-Royce Silver Shadow

The Rolls-Royce Silver Shadow is a luxury car that was produced in Great Britain in various forms from 1965 to 1980. It was the first Rolls-Royce to use a monocoque chassis, a response to concerns that the company was falling behind in automotive innovation....

.

The J. P. Blatchley

John Polwhele Blatchley

John Polwhele Blatchley was a London-born car designer known for his work with J Gurney Nutting and Rolls-Royce Limited.-Career:...

 design was a major change from the pre-war models and the highly derivative Silver Dawn.

As part of a range rationalisation the Bentley S1

Bentley S1

The Bentley S was a luxury car produced by Bentley Motors Limited from 1955 until 1959.Bentley 's first true complete redesign of their standard production car after World War II and their last standard production car with an independent chassis.These cars were given a new V8 engine in late 1959,...

 is very similar, apart from its radiator.
The chassis was a simple steel box section, welded together and very rigid.