Sports car projects : Mini-based ADO70 (1969-1970)

The ADO70 Calypso, a sporting Mini prototype, was built by Michelotti as a proposed low-cost replacement for the MG Midget.

Sadly, this promising idea was canned before it was evaluated too seriously by BLMC’s management.

A sporting opportunity wasted

The original sketches by stylist Paul Hughes. (Picture: "MG: The Untold Story", by David Knowles).
The original sketches by stylist Paul Hughes. (Picture: MG: The Untold Story, by David Knowles)

The ADO70 Calypso was conceived by Harry Webster as a fun car for the US market. However, the project foundered when the prototype met with an apathetic reaction by Leyland’s management, and the required funds were not forthcoming. Although generally known as the Michelotti Mini, it should be noted that it was built – rather than designed – by the Italian company.

And, boy did British Leyland Motor need a small sports car for the USA. In the late-1960s, this was still a huge money earner for the company, and was something of a priority as a consequence. As tried before by BMC with the ADO56 prototype, the Mini was used as a basis for this attempt at a new MG Midget replacement.

Harry Webster tasked designers Paul Hughes and Rob Owen to sketch a Midget replacement based on the Mini, and they quickly came up with a two-seater, targa-topped design that mimicked the Porsche 914 (and original Triumph Bullet and later TR7). On paper, it looked crisp and promising.

Some compromises to ADO70 design

The targa-topped design pre-empted threatened anti-convertible legislation emanating from the USA, but it carried some cost-saving measures expected on a budget sports car. So, it needed to retain the Mini’s 10-inch wheels and, in order to simplify anticipated production costs, it was going to have fixed (not pop-up) headlights set at a height of at least 24-inches.

The prototype being prepared at Michelotti's styling studios in Turin. (Picture: "MG: The Untold Story", by David Knowles).
The prototype being prepared at Michelotti’s styling studios in Turin. (Picture: “MG: The Untold Story”, by David Knowles)

Once the design came together, Webster commissioned Michelotti to create a prototype ADO70 Calypso, and donated a Mini 1275GT to the Turin design studio (above). The carrozzeria created the new body, and the Mini’s running gear was adapted to accept the new body shape and a new steering wheel position.

According to David Knowles’ brilliant book MG: The Untold Story, the prototype was hamstrung by an overweight, handbuilt body, leaking Hyrolastic suspension and damaged driveshafts. However, it was made a runner by Innocenti and was driven back to the UK under its own steam, presumably at quite a modest pace.

ADO70: Styled in Britain, built in Italy, abandoned in the UK

The finished prototype, as photographed for the archives at Longbridge. The car's "GB" sticker bears testament to the fact that it had been driven back from Turin to Longbridge. Paul Hughes is said to have been "disappointed" with the way his original design had been interpreted (and, indeed, altered) by Michelotti. (Picture: "MG: The Untold Story", by David Knowles).
The finished prototype, as photographed for the archives at Longbridge. The car’s GB sticker bears testament to the fact that it had been driven back from Turin to Longbridge. Paul Hughes is said to have been ‘disappointed’ with the way his original design had been interpreted by Michelotti. (Picture: MG: The Untold Story, by David Knowles)

Back in the UK, the ADO70 Calypso prototype was given a lukewarm reception by BLMC’s senior management. In April 1970 the BMC Board had evaluated a wooden mockup of the ADO70, and then again in August following the Michelotti-built car’s return to the UK.

The running prototype might not have been badged as such, but it was intended to have been sold as an MG in the USA. However, on the second viewing, the BMC Board concluded that the A-Series engined front-wheel drive package wasn’t what the Americans wanted – and that its engine would have had a limited future given the Mini replacement projects that were in preparation at the time.

Following its rejection as production proposition, the car was left to rot at Longbridge, parked outside the Exterior Studio, before being rescued and restored. It now forms part of the British Motor Industry Heritage Trust’s collection at Gaydon.

Keith Adams

Editor and creator AROnline at AROnline
Created in 2001 and built it up to become the world's foremost reference source for all things BMC, Leyland and Rover Group, before renaming it AROnline in 2007.

Is the Editor of the Parkers website and price guide, formerly editor of Classic Car Weekly, and launch editor/creator of Modern Classics magazine. Has contributed to various motoring titles including Octane, Practical Classics, Evo, Honest John, CAR magazine, Autocar, Pistonheads, Diesel Car, Practical Performance Car, Performance French Car, Car Mechanics, Jaguar World Monthly, MG Enthusiast, Modern MINI, Practical Classics, Fifth Gear Website, Radio 4, and the the Motoring Independent...

Likes 'conditionally challenged' motors and taking them on unfeasible adventures all across Europe.
Keith Adams


  1. This would have been easily mistaken for a Datsun 100A from the front- but unmistakable for anything from the back- more’s the pity. An interesting dud, but a dud nonetheless.

  2. Agree with you Chris… the front is very much like the mid 70’s Datsun Cherry 100A, but with an air scoop. At least it still exists as an exhibit at Gaydon.

  3. The proportions look to have been lost between drawing and production.. Rather like the difference between Harris Mann’s stylish drawings and the production Allegro.

  4. Would it be correct to say that had ADO70 reached production then it would have been a lot quicker as well as significantly lighter compared to the prototype’s overweight handbuilt body?

    Additionally would the extra weight of handbuilt bodies also explain why the ADO34 and EX234 prototypes were considered slow even with 1275cc Cooper S spec engines or were there other reasons for their lack of performance, since based on the figures of both prototypes it was difficult to believe they were outpaced by the Mini 1275cc Cooper S?

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