The changes to the specification and a collapse in the demand of high performance cars brought about by the early 1990s recession resulted in many buyers choosing not to exercise their purchase options.

[4][9] Racing team owner Tom Walkinshaw approached Jaguar executives and encouraged the company to enter the XJS into the 1981 European Touring Car Championship.

[9][11][13][15] To justify the resources consumed by the project, the XJ220 needed to provide meaningful data to the engineers on handling, aerodynamics – particularly at high speeds – and aluminium structures.

[13] The design brief for the exterior restricted the use of aerodynamic aids and aimed for a simple yet clean and functional body similar to classic Jaguar sports cars, such as the D-Type and E-Type.

[19] Aerodynamic work was undertaken at the Motor Industry Research Association wind tunnel using a 1:4 scale model, as the project was unable to budget for a full-scale mock-up.

[12] The concept car was completed in the early hours of 18 October 1988, the day it was due to be unveiled at the British International Motor Show, being held at the National Exhibition Centre, Birmingham.

[26] The car received an overwhelmingly positive reception by public and press and a number of wealthy Jaguar enthusiasts handed over blank cheques to secure a purchase option should the XJ220 concept go into production.

[13][25] The XJ220 was not initially intended to be a production car, but following the reception of the concept and financial interest from serious buyers, a feasibility study was carried out by teams from TWR and Jaguar.

The list price on 1 January 1990 was £290,000 exclusive of value-added tax (VAT), options and delivery charges, but by 1992 that had increased considerably owing to indexation of contracts.

[28] Richard Owen was appointed chief designer and the remainder of the team was made up of Jaguar and TWR staff, including Pete Dodd, the only member of the group of twelve responsible for the XJ220 concept.

[2] The transmission featured triple-cone synchromeshing on first and second gears to handle rapid starts, whilst remaining relatively easy for the driver to engage and providing positive feel.

[40] The scissor doors were dropped for the production model and significant redesign work was carried out on the design when the wheelbase and overall length of the car was altered.

A number of small design changes for the body were tested in the wind tunnel; the final version had a drag coefficient of Cd=0.36 with downforce of 1,361 kg (3,000 lb) at 200 mph (322 km/h).

[45] The production model utilised the same Alcan bonded honeycomb aluminium structure vehicle technology (ASVT) as the concept car for the chassis.

[46] The chassis design featured two box section rails which acted as the suspension mounting points and would provide an energy absorbing structure in the event of a frontal impact; these were successfully tested at speeds up to 30 mph (48 km/h).

An integral roll cage formed part of the chassis and monocoque, providing additional structural rigidity for the car and allowing the XJ220 to easily pass stringent crash testing.

[2][40] The rear-wheel steering was dropped from the production car to save weight and reduce complexity, as was the height adjustable suspension and active aerodynamic technology.

[5] The rev limiter was increased to 7,900 rpm and the catalytic converters were removed in favour of installing straight-through exhaust pipes for a second series of runs, and it was this attempt which resulted in the maximum recorded speed of 217.1 mph (349.4 km/h).

He was particularly impressed with the throttle response, the driver's ability to control the performance of the car very precisely, and the way in which the engine delivers its power progressively rather than in one short burst.

Barker was also impressed with the engineering, saying "this car is catalysed, fully homologated and has passed the same tests that a Volvo needs before going on sale", going on to discuss how the vehicle looked at home on the racetrack thanks to the design.

"[58] Ergonomics and ride were also praised by Gavin Green in Car August 1992: "you sit straight ahead, pedals and four-spoked Nardi wheel beautifully positioned.

"[60] In a comparison test published in the Car March 1994 issue, the testers liked the "sheer blistering pace, looks and a superb cabin" but its size, the doors not opening far enough and handling were criticised: "If there's a more evil device on our roads, I wouldn't like to find it, for the XJ220 suffers from immense initial understeer followed by violent and snappy pendulous oversteer."

"[61] Motoring journalists have been critical of its size, being too big for a two-seater with virtually no luggage space, too wide to fit through traffic restrictors or to drive comfortably on most roads.

Most criticised was the behavior at low revs, the engine sound was described with words like "a pail of nuts and bolts being poured through a Magimix",[64] rattling clutch, grinding transmission, crackling chassis, rumbling and groaning body contributing to the impression of imminent breakdown.

[76] Richard Piper, Tiff Needell and James Weaver were holding fourth position until an engine failure during the night, ending their race, whilst the second XJ220-C retired after leaving the road.

The XJ220-C was promoted in the United States in the-made-for-TV "Fast Masters" racing series at Indianapolis Raceway Park, airing on ESPN in the summer of 1993 and featuring invited drivers over 50 years old in an elimination format.

[79] The competition became a farce due to the cars' viscous Limited-slip differentials proving ill-suited for the oval track the organizers had chosen, producing strange handling characteristics that resulted in several crashes.

[80] TWR developed a further six road cars called the XJ220-S, featuring one-piece carbon-fibre-reinforced polymer front and rear bodywork; the engine was tuned to 700 PS (515 kW; 690 hp).

The S models were essentially road-going versions of the XJ220-C race car and as a result featured a much simpler race-orientated interior with kevlar seats and the removal of the leather trim.

[4][81] Colin Goodwin, a writer for Autocar, tested an XJ220-S in June 1995 at Millbrook Proving Ground and set the lap record at an average speed of 180.4 mph (290.3 km/h).