Over its lifetime, the FX4 increasingly became regarded as a design classic, and a visual icon of London recognised throughout the world, to the point where its eventual successors - the TX-series and the current LEVC TX - continue the FX4's basic styling cues and overall aesthetic.

Like the FX3, the FX4 was designed by Austin in collaboration with Mann & Overton, the London taxi dealership that commissioned it (and paid for half of its cost) and Carbodies, the coachbuilder that built the body and assembled the cab ready for sale.

The design team included Albert Moore from Austin's engineering division, Jack Hellberg from Carbodies and David Southwell of Mann & Overton.

The original Austin design had a small rear light cluster and roof-mounted turn indicators (commonly known as "bunny ears").

On the revised model, the rear wings were modified with less prominent tailfins to accept the taillights and turn indicators from the MkII Austin 1100/1300.

Sound deadening, black vinyl seats and an altered partition (with an additional 4 inches of legroom) were warmly welcomed.

[2] In 1973, Carbodies' owner BSA, by now confronting imminent bankruptcy, was bought by Manganese Bronze Holdings, who were happy to continue making the FX4.

[2] The old Austin engine was no longer available because, during Michael Edwardes' reconstruction of British Leyland, the plant had been sold to India.

[2] The FX4R had some improvements over the previous FX4 models, including power steering and full servo brakes, but its performance and reliability were poor and the cab gained a bad reputation.

Whilst powerful and reliable, the Perkins conversion gained a reputation for being noisy at idle and, mistakenly, for causing cracks in the chassis.

In order to regain lost sales due to the FX4R's failure, Carbodies took old chassis and suspension components and refurbished them, fitting new bodywork and the original-type 2520 cc diesel engines re-imported from India.

As part of a programme to develop a replacement model, AP Lockheed were commissioned to design and develop front disc brakes, and in conjunction, GKN designed a new suspension system to allow disc brakes to be fitted whilst maintaining the mandatory 7.6 m turning circle.

The very last Fairway made, with registration mark R1 PFX (i.e. RIP FX), was built on 1 October 1997 and was presented to the National Motor Museum, Beaulieu.

In the face of pressure from the trade, TfL allowed different conversions systems to be developed that could be fitted to the Nissan engine to make it comply.

Only 80 Austin and Rover-engined cabs remained on the road, which made it uneconomical to develop conversions for them so they were granted an exemption.

Introduced at the same time as the FX4, it was aimed at the private hire, limousine and funeral trade and this market was the main reason why the petrol engine was offered in the vehicle.

Air conditioning was offered as well as a wider range of luxury interior options, including a cocktail cabinet and custom sound systems.

The FL2 designation was dropped around 1987, but limousine versions of the Fairway were ordered, the most prominent being that belonging to the Crown Prince of Tonga.