• Slide 1 of 51: But the advent of monocoque construction made it much harder to construct a unique car, which is why it's now such a costly business. But every so often a car maker will unveil a road-going machine that's unique, either as a customer commission, a marketing exercise or it could simply be as the basis for a production model which never sees the light of day. Sometimes it's a shame that only the one was made – but sometimes it's not such a bad thing:
  • Slide 2 of 51: Starting out with a 404 cabriolet, Peugeot created a diesel-engined record breaker with a fixed narrow roof and just 69bhp. It ran for 72 hours at Montlhéry, breaking 22 speed records in the process, three of them all-new.

    Peugeot 404 (1966)

    Starting out with a 404 cabriolet, Peugeot created a diesel-engined record breaker with a fixed narrow roof and just 69bhp. It ran for 72 hours at Montlhéry, breaking 22 speed records in the process, three of them all-new.

  • Slide 3 of 51: When the Transit Supervan made its public debut at the Easter race meeting at Thruxton in April 1971, Ford could never have predicted just what an icon this ludicrous machine would become. The bodyshell was a standard Transit Mk1, but it hid a rather barmy secret; this delivery van was based on the chassis of a Ford GT40, complete with mid-mounted 5.0-litre V8.

    Ford Supervan 1 (1971)

    When the Transit Supervan made its public debut at the Easter race meeting at Thruxton in April 1971, Ford could never have predicted just what an icon this ludicrous machine would become. The bodyshell was a standard Transit Mk1, but it hid a rather barmy secret; this delivery van was based on the chassis of a Ford GT40, complete with mid-mounted 5.0-litre V8.

  • Slide 4 of 51: With 435bhp on tap, the Supervan's performance was shattering. We clocked a 0-100mph time of just 21.6 seconds when we drove it at Ford Motorsport's Boreham airfield. We also saw 102mph on the clock – in second gear! It was reckoned that the top speed was 168mph, but Supervan's aerodynamics were so poor that it would have been a frightening experience. Sadly, Supervan 1 was scrapped in the 1970s.

    Ford Supervan 1 (1971)

    With 435bhp on tap, the Supervan’s performance was shattering. We clocked a 0-100mph time of just 21.6 seconds when we drove it at Ford Motorsport’s Boreham airfield. We also saw 102mph on the clock – in second gear! It was reckoned that the top speed was 168mph, but Supervan’s aerodynamics were so poor that it would have been a frightening experience. Sadly, Supervan 1 was scrapped in the 1970s.

  • Slide 5 of 51: When business tycoon Gianni Agnelli (1921-2003) owned Fiat he could have whatever cars he wanted and a whole raft of one-offs were built for him. Among them was a five-door estate based on the ultra-luxurious Fiat 130 saloon, with its 3.2-litre six-cylinder engine rated at 165bhp.

    Fiat 130 Familiare (1971)

    When business tycoon Gianni Agnelli (1921-2003) owned Fiat he could have whatever cars he wanted and a whole raft of one-offs were built for him. Among them was a five-door estate based on the ultra-luxurious Fiat 130 saloon, with its 3.2-litre six-cylinder engine rated at 165bhp.

  • Slide 7 of 51: When Aston Martin developed the incredibly futuristic mid-engined Bulldog, there was talk of building up to 25 of the Williams Towns-designed machines. With electrically operated gullwing doors, a twin-turbo V8 cranking out 700bhp and the most dramatic proportions imaginable, it’s likely the necessary buyers could have been found.
  • Slide 8 of 51: With a verified near-200mph top speed, this would have been the world’s fastest production road car without doubt. But with all of the development work done, Aston Martin changed hands and the new owners didn’t feel this was the way forward for a quintessentially English car maker. So the sole Bulldog built was sold instead, but it still survives and is currently having a nut-and-bolt restoration by Classic Motor Cars in Shropshire.

    Aston Martin Bulldog (1980)

    When Aston Martin developed the incredibly futuristic mid-engined Bulldog, there was talk of building up to 25 of the Williams Towns-designed machines. With electrically operated gullwing doors, a twin-turbo V8 cranking out 700bhp and the most dramatic proportions imaginable, it’s likely the necessary buyers could have been found.

  • Slide 9 of 51: With Audi busy conquering rally stages the world over, with its incredible Quattro, Volkswagen wanted a piece of the four-wheel drive action so it came up with this – a Scirocco with a 1791cc four-pot engine at each end. Thus equipped there was a healthy 360bhp available to give a 180mph top speed and 0-62mph in just 4.5 seconds. VW built two of these Sciroccos; one for testing and one for show use.

In the early days of the car, when they were hand-made and based on a separate chassis, it was easy to build one-offs.

But the advent of monocoque construction made it much harder to construct a unique car, which is why it’s now such a costly business. But every so often a car maker will unveil a road-going machine that’s unique, either as a customer commission, a marketing exercise or it could simply be as the basis for a production model which never sees the light of day. Sometimes it’s a shame that only the one was made – but sometimes it’s not such a bad thing: