But they were only scratching the surface of what’s possible when you let unconventional cars loose on a racing track. Trackside’s Keith Collantine picks five of his favourites.

View our slide show of AMAZING crazy racing cars

Suzuki Escudo / XL7 Pikes Peak Rally Car

Made famous by the Gran Turismo racing game series, the Suzuki Escudo rally car (and its successor, the XL7) was designed to tackle the fearsome Pikes Peak rally in America.

This is a 20km blast up Pikes Peak in Colorado, which includes 1,439m of gradient and one infamous turn known as ‘Bottomless Pit’ with a 1,800m drop on the outside.

Japanese star Nobuhiro ‘Monster’ Tajima holds the all-time record for the climb in his Suzuki XL7 Hill Climb special. The XL7 is based on the Suzuki Vitara – but with a twin-turbo 3.6-litre V6 engine pumping out a colossal 1,000bhp.

Read more: Incredible 1,000bhp rally car

Tyrrell P34 Six-wheeled Formula 1 Car

Ken Tyrrell built Formula 1 cars out of an old wood yard in the sixties and seventies. But after winning three championships with Jackie Stewart his team struggled to compete with the likes of Ferrari and McLaren.

Designer Derek Gardner dreamt up a radical way of improving the car’s cornering – he added an extra pair of wheels at the front for steering.

The car not only raced, it was competitive, and Jody Scheckter took it to victory at the 1976 Swedish Grand Prix. It completed another year’s service before being dropped.

A couple of teams, including Williams, tried to resurrect the idea in the 1980s, until the sport’s governing body banned six-wheeled cars. Spoilsports.

Read more: 6-wheel F1 car

Volvo 850 Estate Touring Car

Volvo’s first entry to the British Touring Car Championship in 1994 brought them instant cult status. The Swedish manufacturer chose of the practical but unsexy estate cars it’s best known for to take on the world’s top touring car stars around the race tracks of Britain.

The cars were run by Tom Walkinshaw Racing, who steered Jaguar to Le Mans success in the 1980s. Jan Lammers and Rickard Rydell couldn’t get much out of the 850s at first but after a rigorous development programme Rydell got one on the podium at Snetterton in Norfolk.

Sadly it was replaced with a conventional saloon in 1995.

Read more: Five decades of great British touring cars

Volkswagen Caddy Van Racing Car

A pair of these unusual racing machines can often be found battling in the Volkswagen Cup series.
 
The championship regulations are aimed to equalise car performance, so the Caddys can be seen doing battle with Golf R32s and GTIs.

Oh, and it’s a diesel as well…

Renault Espace F1

OK, not strictly a racing car, but it did contain an awful lot of one. In fact Renault lifted the engine, transmission and rear suspension from the championship-winning Williams FW14B.

They then packed it into their iconic Espace MPV to create a vehicle capable of 194mph while carrying a full load of shopping.

The Espace F1 appeared at many motoring events and enraptured motor racing fans with its combination of dowdy family car looks paired with the V10 wail of a Formula 1 car.

Renault isn’t the only manufacturer who was tempter to stick an F1 engine where it doesn’t belong: Ford built the Transit Supervan.

Read more: The cars money can’t buy

View our slide show of AMAZING crazy racing cars