The one in the film was a tube frame special with rally suspension and a V8 in the back, the production car was to be a massively complex high revving 4 cyl turboed Cosworth lump with gas turbine assisted hybrid system...The Mercedes One is most similar in concept with it's F1 derived "Power Unit".
Note quite
The first proto was a gas turbine setup with electric motor hybrid (there are still bits on peoples desks), the follow on cars were a screaming 1.6 Williams produced petrol plus the hybrid, made for a very impressive performance and a few years before any other hybrid super cars were about.
Major issue was getting enough engines from Williams, although they now use much the same setup in V12 for the new Aston.
The motor and drive system made its way into the iPace, many of the design hints externally hit the F-Type, JLR learned a lot from it.
But a truly stunning car, there are a couple in storage at classics (well worth a visit, I think one was the Bond motor), one in the heritage centre at Gaydon, and a few more in 'storage'