The Sigma, unveiled on 13 March 1969 in Geneva, was a prototype that was never intended to compete in any Formula One races.
[2] The main inspiration for creating the car was the high number of fatalities among Formula One drivers due to low safety standards.
[3] The Sigma was built in 1969 in cooperation by Pininfarina and Revue Automobile with the support of Enzo Ferrari, Fiat and Mercedes.
[3][4] The name of the car ("Sigma") was chosen because several years before Pininfarina had built an experimental safety vehicle with that name, a 1963 Pininfarina PF Sigma.
There were many innovations in it, such as a driver survival cell, multi-layer fuel tanks, a fire extinguisher system, plastic fuel-tanks, a safety-belt-system and sidepods protruding behind the rear wheels to prevent interlocking wheels.