Gallery: 1970 Mazda concept that 'got the green light'... and was then forgotten

You wouldn’t know it at first glance, but the Mazda RX500 concept of 1970 was developed as a ‘mobile test bed for high-speed safety’. In reality, it looks like a car of the future… 1970s style. Wedge styling and gullwing doors make it look very much of its era. It also has a neat concept car style extravagance. At the back of the car, green lights come on under acceleration, amber during constant speed and increasing number of red during braking. Is this the only concept car in history to ‘get the green light’ but not go into production?

With a remarkable 247bhp from its 491cc rotary engine, you might be forgiven for expecting rather a lot of acceleration, but the 850kg machine achieved a relatively modest 125mph top speed.

For some time, it was believed that three RX500s had been built – one green, one yellow and one silver. However, when the car was restored in 2008, all three colours were found in different layers, suggesting one example had plated the role of all ‘three’. After years of neglect, the car was displayed at the Tokyo Motor Show. Its appearance on the Cartier Style et Luxe lawn marks its very first appearance in the UK.

Photography: Richard Pardon