It would be a trick question to ask how many three-wheeled cars have made it on to a Formula 1 podium, but at the same time, it is almost true that this happened.
No F1 car was designed to have three wheels, the Reliant Robin never having had much impact in F1 circles, but drivers have been known to knock wheels off their cars, now and then. Philippe Streiff crossed the finish line at the very first Formula 1 Australian Grand Prix in 1985, on the streets of Adelaide, with all four wheels just about attached, but the front left was not in any regular contact with the road, being dragged along, held on to the car by the remaining suspension links that had not been broken when he collided with his own Ligier-Renault team-mate Jacques Laffite at the hairpin on the penultimate lap.
The race was held in early November and the South Australia city was sweltering in 95-degree F temperatures. This meant that a lot of cars retired but Keke Rosberg, driving a Williams-Honda, somehow managed to get to the chequered flag without overheating, while most of the field disappeared because of the heat. There were engine failures, fires, electrical problems, broken transmissions and overheating brakes and after 81 laps only Rosberg and the two Ligier-Renaults were on the same lap. Laffite, Keke’s former Williams team-mate, was being chased by Streiff, with the Tyrrell-Renault of Ivan Capelli, another lap behind, but nonetheless ahead of the delayed Ferrari of Stefan Johansson and an Arrows-BMW driven by Gerhard Berger.
Rosberg was already on his final lap when the two Ligiers collided and, with Capelli taking the chequered flag just behind Rosberg, there was no pressure on Streiff, who limped around the track, hoping that the wheel would stay attached to the car. He made it, to score what would be the best result of his career, although Guy Ligier was unimpressed that Streiff had risked wiping out both cars with his move. In the end, Ligier decided not to offer him a drive for 1986, taking the veteran René Arnoux and leaving Streiff to drive a Tyrrell, thanks to backing from Elf.
* In Germany in 1987 Stefan Johansson finished with four wheels, but only three tyres. Does that make it a three-wheeler?