sentences:  Thus Mercedes-Benz, Toyota, Panoz, BMW, and Audi turned to the prototypes class, either using open cockpit prototypes or closed cockpit cars which were actually evolutions of their former GT cars.Nissan, believing that a purpose built prototype would be superior to an evolved GT car, decided to go the route of an open cockpit.Nissan turned to the UK based firm G-Force Technologies to design and build the R391.