 When the original Can-Am series ceased at the end of 1974, McLaren were by far the most successful constructor with 43 wins.McLaren first contested the United States Auto Club's (USAC) Indianapolis 500 race in 1970, encouraged by their tyre supplier Goodyear, which wanted to break competitor Firestone's stranglehold on the event.With the M15 car, Bruce, Chris Amon, and Denny Hulme entered, but after Amon withdrew and Hulme was severely burned on the hands in an incident in practice, Peter Revson and Carl Williams took their places in the race to retire and finish seventh, respectively.