Development began in 1958 with XC9002, a scaled-down version of the 1956 Issigonis XC9001 prototype; however, this was soon thought to look too much like BMC's new Mini.

In-house attempts to distance the style of the new car from that of the Mini, such as this mock-up produced by the Morris factory later in 1958, were less than successful. In fact, according to production engineer Reg Job, it was the "plain and uninteresting" frontal design of this car that prompted the commission for Pininfarina to re-style it.

By January 1959, Pininfarina had produced this comprehensive re-working of the original XC9002 proposal. This version was considered to be too complictated (and therefore too costly) to put into production, but a simplified version was scaled-up as a proposal for the ADO17 project.

Pininfarina's second, simplified offering of 1959. Now codenamed ADO16, the front is much tidier (though with a makeshift bumper), and the door frames have been smoothed out.

Alternative (nicer?) less gaping front-end treatment from July 1959, on the same body as above. Door frames would change again before it reached production.

Even before the Austin 1100 had reached the marketplace, plans for an estate version of the ADO16 were already at an advanced stage, as demonstrated by this photograph of the split-tailgate prototype from May 1963; after all, the car's main Ford rivals – the Anglia and Cortina – were both available in estate form. However, demand for the saloon versions proved to be so strong that the estate body didn't see the light of day until March 1966, when it was launched simultaneously as the Austin 1100 Countryman and Morris 1100 Traveller. This delay meant that it was produced for just 18 months in MkI form, and when the MkII version arrived in Autumn 1967, the rear bodywork was carried-over wholesale.

This facelifted version of ADO16 was investigated prior to the 1968 merger. It appears to bear the hallmark of Roy Haynes, particulary in the way the headlamp/indicator set-up resembles that of the MkII Ford Cortina.

This rebodied 1100 was considered as a more radical alternative to the facelifted car. There was also a revised Hydrolastic suspension system under development for this car, but the project was cancelled by the Leyland management in favour of ADO67.

Consideration was also given to extending the Issigonis 9X supermini into an ADO16 replacement. Compare this with the proposed ADO16 facelift shown above. (Both cars eventually lost out to the Allegro.) This design also bears a passing resemblance to the Autobianchi Primula, which itself looked rather like an ADO16 hatchback.

This modified ADO16 is one of five cars produced under BLMC's Safety Research Vehicle (SRV) project in 1974. Designated SRV5, the car featured a spring-loaded pedestrian-catching cage which was activated in the event of an impact. Thus, it would be raised from its dormant position atop the front bumper in order to prevent the accident victim from sliding down into the path of the car's wheels. Well, that was the theory, anyway...