Presented as a saloon at the London Motor Show in October 1958, the A40 Farina was intended to replace the Austin A35, from which it inherited much of its running gear, and was a capacious thoroughly modern small car, with a brand new distinctive two box shape and headroom in the back seat. It was a saloon, the lower rear panel dropped like a then conventional bootlid, the rear window remaining fixed.

The Countryman hatchback appeared exactly a year later in October 1959, and differed from the saloon in that the rear window was marginally smaller, to allow for a frame that could be lifted up, with its own support, while the lower panel was now flush with the floor and its hinges had been strengthened. It was a very small estate car with a horizontally split tailgate.

At launch the car shared the 948 cc A-Series straight-4 used in other Austins including its A35 predecessor. The suspension was independent at the front using coil springs with a live axle and semi elliptic leaf springs at the rear. The drum brakes were a hybrid (hydromech) arrangement, hydraulically operated at the front but cable actuated at the rear. The front drums at 8 in (200 mm) were slightly larger than the 7 in (180 mm) rears. Cam and peg steering was fitted.

Individual seats were fitted in the front, with a bench at the rear that could fold down to increase luggage capacity. The trim material was a vinyl treated fabric. Options included a heater, radio, windscreen washers and white-wall tyres. The gearchange lever was floor-mounted with the handbrake between the seats. The door windows were not opened by conventional winders, but pulled up and down using finger grips; a window lock position was on the door handle.

Vanguards modelled the Mark 1 version of the car, in production from 1958 to 1961 when the facelifted Mark 2 was launched with a restyled front end, longer wheelbase and a bigger engine.