The Rover P8 was intended to replace P5 and P6, and become the flagship model using the then new all-alloy V8. Approval was given for production in late 1967.

Following the formation of BLMC in 1968, internal struggles led to a delay in the programme and several significant figures within the company did not support the project.

Various prototypes were tested at Motor Industry Research Association (MIRA) test facility. It is said that the car's safety issues following the failure of the 30 mph front impact test and the need for extensive and expensive redesign meant the project was unaffordable. The P8 project was cancelled in 1971.

This vehicle is one of those running prototypes and badged as "Mantelay" to fool onlookers.