At the very start of the 6R4 project, the design team actually considered a conventional layout for the car but quickly rejected a front-engined V6 Metro with rear wheel drive, primarily due to the driver having to sit so far back that he couldn't actually see the front of the car! The team would perhaps have been happier from a packaging point-of-view to use the forthcoming larger Maestro bodyshell but the initial funds came from the Metro marketing men and thus it had to be the smaller car. As Austin Rover Motorsport Director John Davenport commented positively at the 1984 launch, "A small car makes a small track look bigger!".

After much discussion concerning layouts, the 'VHPD' (Very High Performance Derivative) emerged as a mid-engined, four wheel drive Metro. The original concept for the car was for a range-topping 'Executive 2+2 GT' sort of machine and, as such, a rudimentary 'bench seat' (behind the front seats) appeared on the Williams Grand Prix Engineering designed prototypes, and still survives to this day on the final production run of cars - not that you would ever really want to (or be able to) sit there!

The first recorded accident in a 6R4 occurred at Chalgrove Airfield in Oxfordshire, when test driver Steve Soper rolled the original prototype into a field after hitting some standing water at about 90mph on slick tyres ! Williams F1 engineer John Piper was in the co-driver's seat at the time. Both occupants were unharmed and John Davenport shrugged off the incident, stating that "these things happen...we'll learn something from it !".

The 6R4 bodyshell was designed by F-18 fighter jet engineer and current Williams F1 Chief Composites Engineer, Brian O'Rourke - his first project for the company and his first steel monocoque design.

The V64V (V6 with 4 Valves per cylinder) engine is still believed to be the only purpose-built rally engine, designed specifically for motorsport use. All other works rally cars using high-performance derivatives of production engines. Originally, it had been thought that the car might be fitted with a Honda V6 but the F2 engine was NOT a rally engine and the road-going V6 with its complex valve train was unsuitable for tuning. Finally, ARG Motorsportís Engineering Manager David Wood assembled a team to design and produce a prototype within eleven months.

All the cars after the first four prototypes (001 ñ 004) were built at Austin Roverís Longbridge factory on a special production line adapted from one used previously to produce quantities of pre-production prototypes. All this was arranged and run under the supervision of Mike Barnett. After completion, the cars were stored in a compound before being transported down to ARG Motorsport at Cowley. Body shell number thirteen was the first production 6R4 to be "passed off" by Quality Control at Longbridge, destined for the Frankfurt Motor Show.

A656 NJO, one of the three initial prototype 6R4s, was featured in Yorkshire Television's drama series "The Winning Streak", screened nationally from September 1985.

The final version of the 6R4 consisted of three hundred and forty-seven unique panels nearly all of which were made at the Pressed Steel facility at Swindon and brought up to Longbridge by rail just like all the standard Metro parts made in Swindon. Only sixteen panels were taken un-modified from the standard production Metro. The roof panel was fabricated at Longbridge from aluminium and, using what was then a revolutionary technique, glued onto the bodyshell.

Even some of the standard-looking components taken from the Metro production line had to be modified for use in the 6R4. The MG Metro dashboard required modification to fit the 6R4 bodyshell and even the standard headlamp units had to be cut away at the rear to make room for the massive front inner wings!

The MG Metro 6R4 had the distinction of scoring the first-ever victory for a British driver on a Finnish rally when Malcolm Wilson won the 1986 Mantta Rally in Tampere some weeks prior to the 1000 Lakes Rally.

The press launch for the 6R4 project was held at the London Heathrow hotel in February 1984, where Tony Pond and Rob Arthur drove the prototype car down a ramp through a huge cinema screen that was showing a head-on shot of the car. They pulled it up just short the front row of journalists gathered for the event!

When the first prototype car was handed over to Austin Rover Motorsport by Williams in February 1983, the car was completely red. It only acquired its white roof later.

When the 6R4 made it's competition debut on the 1984 York National Rally it had acquired a white roof to compliment it's red paintwork - a colour scheme reminiscent of the earlier works Austin Healey and Mini rally cars from the BMC Competitions Department at Abingdon. Despite setting eight fastest stage times, Tony Pond was forced to retire from the event when a cam follower picked up and it was withdrawn rather than destroy the engine.

German engineer and former Kremer racing employee Bernie Marcus was involved in the wind tunnel testing at MIRA, where it was discovered that air was being sucked out of the cooling scoops rather than being forced into them ! Various hasty redesigns were necessary and at the same time the 390mm Michelin wheels and tyres were adopted also requiring some redesign of wheel arches and suspension.

The first rally victory for the prototype 6R4 came on the Gwynedd Rally in March 1985,in the hands of Tony Pond and Rob Arthur.

The original development engine fitted to the prototype cars was derived from the Rover V8 power plant with two cylinders cut out and the cylinder block/head and other components welded back together. Designated the V62V (V6 and 2 Valves per cylinder), this engine featured several internal parts from the Group A Rover Vitesse engine plus some unique components. It was fitted with triple downdraught Weber carburettors that used to backfire and occasionally catch the air filters on fire. Five such engines were built.

The final version of the 6R4 bodyshell contained an amazing 137ft of welding compared to just 4ft on the standard production Metro plus 25% more spot welds.

A 2.3-litre bi-turbo engined 6R4 won the 1992 European Rallycross Championship in the hands of Whitstable driver Will Gollop.

The V64V engine also powered the Ecurie Ecosse Group C2 racing team to victory in the 1986 World Sportscar Championship. The team drivers were Ray Mallock and Marc Duez (who also campaigned a 6R4 in various European Rally Championship events during the same year).

Didier Auriol and Bernard Occelli won the 1986 French Rally Championship in their RED-prepared 6R4, one of five championships won by 6R4 crews during the 1986 season.

In the UK, David Llewellin/Phil Short gave the 6R4 it's first international rally victory on the 1986 Circuit of Ireland. Their winning margin over Russell Brookes' Opel Manta 400 was almost 9 minutes!

The 6R4 was homologated into Group B by FISA (motorsport's world governing body) on November 1st, 1985 ñ just in time for the RAC Rally ñ and was given the homologation number B-277.

In 1991, after Tom Walkinshaw had bought the rights and the design from ARG, Jaguar adopted the V64V engine design for their XJ220 supercar, increasing the engine's capacity to 3.5 litres and fitting twin turbochargers. The normally aspirated engine had earlier been installed in MG's EX-E concept car.

Scottish driver Alastair Brearley campaigned a supercharged 6R4 during 1986/87. His 3-litre V64V-engined car was fitted with twin Sprintex superchargers and produced 20% more power than standard. ARG were already looking at using Sprintex on their Group S engine for the category that was scheduled to replace Group B in 1988.

Austin Rover claimed the team prize on the 1986 Lombard RAC Rally with 6R4s finishing in 6th, 7th, 8th and 9th places.