Top Gear's Top 9: genius racing loopholes

Every McLaren road car since the MP4-12C has had a system called ‘BrakeSteer’. It’s inspired by a system dreamt up for the 1997 F1 car, where a second brake pedal was used to slow wheels on one side of the car – and changed depending on whether there were more left- or right-handers.

Mercedes’ 2020 F1 car featured Dual-Axis Steering, or DAS. By telescoping the steering column in and out by thrusting the steering wheel, the drivers could adjust the toe-in/out angle of the car, reducing drag on the straights and aiding tyre warm-up under a safety car.

Moveable aero devices (besides DRS, of course) aren’t allowed in F1. McLaren got round that in 2010 with its F-duct, which relied on the driver moving their knee to cover a hole in the cockpit side and blocking the duct, stalling airflow over the rear wing when downforce wasn’t needed.

With 2009’s cars subject to major aero rule changes and McLaren and Ferrari floundering, the secret to Brawn’s success was the ‘double diffuser’ design which vastly increased the surface area of the downforce-generating bodywork at the back of the car.

In the Nineties, the rules for endurance racing said you had to build a run of road-going homologation cars. Part of the rules insisted the car had a boot big enough for a briefcase. Toyota immediately declared the empty space in the dry fuel tank be counted as the boot as it was capable of containing a briefcase.

Gordon Murray employed a fan to suck air out from under his 1978 BT46 F1 car, increasing its ground effect even in slow corners and allowing higher cornering speeds. It won on its debut by 34 seconds, before the sport’s governing body insisted it was withdrawn for the rest of the 1978 season.

Want to run a lighter car than the official rules allow? Do what Williams did in 1982 and fit a large water tank in the sidepods supposedly there to hold water needed for brake cooling. They never actually ran that hot, and a few laps later the water in the tank would evaporate or be dumped.

In 2011 the RB7 was spotted to have wings that bowed under load, sparking against the track in the pursuit of increased ground effect. Thanks to clever layering of the wing, it would remain firm during FIA tests but bend under the higher loads experienced in the race.

The ex-WW2 pilot turned racecar driver and team owner has a string of rule-bending innovations to his name, including hiding a basketball in a fuel tank during scrutineering then deflating it after the inspection so his larger fuel tank could hold more gas and the car needed fewer pitstops.