1965, Indy: Jim Hurtubise and Andy Granatelli with the Novi, one of just five front-engine cars that qualified starting 10th on the grid. It exited on the first lap with transmission problems in a race handily won by Jim Clark, the first victory for a rear-engine car at Indy. Side note: Clark ran the entire race on one set of tires.
Indy 500, 1967: Jim Clark's Lotus expired after just 35 laps. In fact, the last-placed finishers of the race were Mario Andretti, Jim Clark, Graham Hill and Lloyd Ruby, all with mechanical difficulties.