Here we find a Rover T4 which, happily in the view of the day that's in it, is green. More to the point it's got a gas turbine engine sitting where we would normally expect to find a piston one.
The jet engine was developed for aviation use in the 1930s and by the 1950s was becoming almost universal for faster aircraft. It was smoother than a piston engine, produced a lot of power from a relatively small package, had fewer moving parts, had a long life and could be persuaded to run on any kind of liquid fuel you could get into it. So it might be a good thing for a car? Several makers thought so and set about experimenting. Rover's first contribution was the Rover-BRM turbine racer which ran at Le Mans in 1963 (experimental class, would have been eighth) and 1965 (two litre class, finished tenth).
Rover had previously built the T4, essentially a prototype of the P6 but with a 140 hp turbine shoehorned in. They had to design the front suspension to allow for the turbine and this feature carried through to production, just in case. Reports at the time were that the car performed quite impressively once you got used to the engine idling at about 40,000 rpm and an extreme version of turbo lag. Oh, and you needed to discourage people standing directly behind when ticking over (at 40,000 rpm) lest the heat from the exhaust singe them.
Sadly, heavy fuel consumption at low speeds, throttle lag, high costs and that hot exhaust meant we've never seen a production gas turbine car.