I've owned numerous S series Bentleys and Rolls-Royce Clouds. This is a computer mock-up. Note the placement of the rear window compared to the fastback roof line. It's the standard rear window placement. Also note the lack of a fastback roof panel on the back side, should someone claim it's an indented rear window.
Now about installing a Merlin engine; I've ridden in a Merlin equipped trainer fighter [2 passenger - I can't fly one!], and they have something like 2,500 HP. Plus, these engines are way too massive top to bottom to fit under that hood [bonnet]. I was at a Rolls-Royce club meet years ago where a member brought a Merlin attached to a large flatbed trailer. He towed it with a big Chevy Suburban. They used about 12 big truck rear axle shafts, driven into the ground on all 4 sides of the truck & trailer, then chained tight. Even with all that securing, they could only run it at a fast idle, and the axle shafts looked like they would pull out of the earth! And even if you could fit it in there, you would need a radiator 2 times the entire frontal area of this car just to keep it from overheating at idle, not to mention running down the road!
