From a previous Christie's auction listing:
"Unfortunately the Quattroporte II remained as a prototype. Some people say only one car was produced other sources say 13. Both opinions are right, the first prototype, Chassis number 002, was never finished completely as it was used for crash testing and was destroyed. The second prototype, the car offered here, is the sole car which was built to perfection including digital instruments, a wooden dashboard and the very special magnesium wheels. Furthermore Chassis number 004 was the car presented to the public at the Maserati stand on the Paris Motor show in October 1974. Due to various problems on the financial side and with the homologation of the new prototype, Maserati decided to produce with the remaining parts a limited series of 11 cars which were sold to the Middle East, although these cars did not have a lot in common with the first prototype. In order to keep the financial damage as limited as possible these cars were fitted with various older parts from the Quattroporte I.
It is believed that the factory sold this car to an Italian dealer and the present owner purchased the car in 1997 from Autosport Bologna, Italy. Due to a lack of time, he has used and showed the Quattroporte very rarely, but always at prestigious events such as the Cartier Style et Luxe concourse during the Goodwood Festival of Speed in 2000 and 2005."
PH