The McLaren M23 designed by Gordon Coppuck, with input from John Barnard, was a development of the McLaren M16 Indianapolis 500 car and almost uniquely proved to be a Grand Prix winning car over 5 seasons 1973-1977 winning 2 World Drivers Titles, 1974-Emerson Fittipaldi and 1976-James Hunt and the Constructors World Title in 1974.M23/12 was the last works M23 and raced for the team by Jochen Mass.