The Audi Quattro was the first rally car to take advantage of the then-recently changed rules that allowed the use of four-wheel drive in competition racing.

[4] To commemorate the success of the original vehicle, all subsequent Audi production automobiles with this four-wheel-drive system were badged with the trademark quattro with a lower case "q" letter.

[9] The engine was eventually modified to a 2,226 cc (136 cu in) inline-5 with 10 valves, still generating 147 kW (200 PS; 197 hp), but with peak torque lower in the rev-range.

[4] In 1989, it was then changed to a 2,226 cc (136 cu in) inline-five 20-valve DOHC setup generating 162 kW (220 PS; 217 hp), now with a top speed of 230 km/h (143 mph).

Originally, the car had a flat front grille featuring four separate headlamp lenses, one for each of the low and high beam units.

[12][13] The small Subaru Leone station wagon offered an optional part-time 4-wheel drive system in the US market starting in 1975.

Audi built 200 special edition cars in 1988 with the WX engine and analogue instrument cluster, with everything else identical to the MB model of that year.

Beginning with a photograph in the magazine of a Quattro cornering hard on Pendine beach in South-west Wales, Autocar's Road Test Editor raved about the Quattro's "thrilling performance" being impressed with its traction and acceleration particularly on wet, greasy and slippery surfaces, noting that only the Porsche 911 could match its traction and acceleration in slippery conditions.

After extensive driving across the mountain roads of Wales, the Road Test editor mentioned that while the 60/40 front/rear weight distribution can make the Quattro "tricky in extremis" under very hard cornering, the editor wrote that "When driven with respect, once you have learned its ways, the Quattro is nevertheless magnificent, particularly through a wet and deserted roundabout or series of open bends."

The road test editor praised the interior's "comfortable refinement" and judged that its 1981 £14,500 price tag "is very good value for money considering its performance and the fact that its BMW, Porsche and Jaguar rivals cost £5000 more."

The car was a rolling test bed for a future mid-engine sports car and featured a 5-speed manual gearbox, a modified version for the quattro four-wheel-drive system, aluminium body panels with a tubular steel space frame, 1,100 kg (2,425 lb) kerb weight and a suspension system with trapezoidal links.

The revolutionary design features depicted on the concept car would eventually make their way on future Audi models.

[17] The concept utilised aluminium and carbon fibre construction which helped to achieve a total dry weight of 1,300 kg (2,866 lb).

The dashboard featured an LCD console displaying vital information about the car and buttons arranged in a vertical way on the binnacle harked back to the original Audi Quattro.

The Quattro four-wheel-drive system used in the concept was a rear-biased design utilising a two-stage differential distributing power front and aft through planetary gears.

[20][21] The show car features angular flat C-pillars, as well as rectangular double headlights featuring Audi's Matrix LED technology, a spoiler at the lower edge of the rear window, rectangular tail lights, 21-inch wheels, carbon fibre-ceramic brake discs, bucket seats with integrated head restraints, multifunction sport steering wheel, two driving modes (race and setup) in virtual 3D displays, Audi MMI control unit, and air conditioning.

A liquid-cooled 14.1 kWh lithium-ion battery is located at the rear, and the range is claimed up to 50 km (31 mi) on electric power alone.

Largely based on the bodyshell of the road-going Quattro models (in contrast to the forthcoming Group B cars), the engine of the original competition version produced approximately 304 PS (224 kW; 300 hp).

[4] Over the next three years, Audi would introduce the A1 and A2 evolutions of the Quattro in response to the new Group B rules, raising the power output of the turbocharged inline 5-cylinder engine to around 355 PS (261 kW; 350 hp).

Two examples of the same car completely dominated the South African National Rally Championships during 1984 to 1988, with S.A. champion drivers Sarel van der Merwe and Geoff Mortimer.

In addition to Group B competition in rallying, the Sport Quattro won the 1985 Pikes Peak International Hill Climb with Michèle Mouton in the driving seat, setting a record time in the process.

[4] However, the turbocharger utilised a recirculating air system, with the aim of keeping the unit spinning at high rpm, when the driver closed the throttle, either to back off during cornering, or on gearshifts.

[4] In addition to the improved power output, an aggressive aerodynamic kit was added that featured very distinctive wings and spoilers at the front and rear of the car to increase downforce.

[30] The original vehicle (also used in the Children in Need Top Gear crossover mini-episode) lacked a sunroof which was present on the car(s) used in series 2 and 3, hence a fake one was added for the sake of continuity.

[31] In the run-up to the 2010 general election, a campaign poster by the incumbent Labour Party government portrayed Conservative Party and opposition leader David Cameron as Gene Hunt sitting on the bonnet of the iconic red Audi Quattro and urged voters not to allow Cameron to take Britain "back to the 1980s" by electing his party into government amid fears that it would lead to a repeat of the social unrest and unemployment that Margaret Thatcher's Conservative government of that era oversaw.

The image was then adopted by the Conservatives, with the slogan "Fire up the Quattro, it's time for change",[32] with the comment 'Idea kindly donated by the Labour Party'.