The Y-type saloon, introduced in 1947, was completely new. It was the first Morris group car to use independent front suspension with coil springs and rack-and-pinion steering. These features were the work of Alec Issigonis, then a young engineer with Morris Motors.

This particular YB is one of the MG works rally cars. It was successfully rallied by Len Shaw in events such as the RAC, London, Morecambe and Daily Express rallies, as well as a wealth of other trials. Len had been using the Y-type in competitions since the late 1940s.