The image was mocked up by the Leicester-based firm as a design exercise only and there are currently no plans to put the Roadster into production.
Managing director Peter Boutwood did, however, tell Autocar that an M600 Roadster was “not completely out of the question” if the demand was there.
“We could see it being popular in China”, Boutwood added.
Power for the coupe supercar comes courtesy of a twin-turbocharged 4.4-litre V8 unit, which delivers 650bhp at 6800rpm and 1.0bar of pressure, and 604lb ft of torque at 3800rpm. The sprint to 62mph is dispatched in 3.5sec and top speed achieved at 225mph.
If the Roadster variant were to make production it would be based on the current £200k M600 coupe model, making the drop-top one of the fastest and most powerful convertibles in the world.