Read about the facts of this model: This car was produced from 1965 to 1980 and was the first to be produced as a unit Body and Chassis, since its predecessor Cloud III was a chassis and body like modern heavy pick-up trucks.
They made about 30,000 cars, the first-generation Shadow I were produced up to 76/77 and after that whey call is Shadow II.
The first cars Rolls Royce produced in 1965 were more powerful due to bigger carbs. Due to US smog regulations that start to project at the time, they replaced them with smaller ones making the HP much lower and so the emissions.
On the last year of production, some of the 1980 models came out with fuel injection, making it more reliable.
Other related models are:
Silver Wraith II
Camargue
Corniche 2 door Saloon
Corniche Convertible.
All made under the same platform.
To me this car is built like a truck, drives like you are floating in water and the seats feel like your living room couch.