MG Metro 6R4 Clubman
The MG Metro 6R4 is one of the most extraordinary homologation specials ever created, a car that transformed the humble Austin Metro shopping car into a mid-engined, all-wheel-drive, V6-powered Group B rally weapon. The '6R4' designation was straightforward: 6 cylinders, Rally car, 4-wheel drive. The project was developed by Williams Grand Prix Engineering (the Formula One team) under the direction of Patrick Head, with the aim of creating a British contender for the fearsome Group B rally championship.
The 6R4's most remarkable feature was its engine: a 3.0-liter V6 mounted amidships, behind the driver and ahead of the rear axle. This engine, coded the V64V (V6 4-valve), was a naturally aspirated unit with four valves per cylinder and twin overhead camshafts per bank. In Clubman (road-legal homologation) specification, it produced 250 horsepower. In full International rally specification, output reached approximately 410 horsepower. The engine was noteworthy for another reason: it later evolved into the Rover KV6 engine that powered various Rover and Land Rover vehicles, one of the most unlikely family trees in automotive history.
The all-wheel-drive system used a Ferguson viscous coupling center differential to distribute power between the front and rear axles. The FF Developments/Hewland five-speed gearbox was a heavy-duty unit designed to withstand the violent power delivery of rally driving. The drivetrain was designed for maximum traction on loose surfaces, with the viscous coupling providing a simple, reliable torque-split mechanism.
Visually, the 6R4 bore almost no resemblance to the standard Metro. The bodywork was massively widened to accommodate the wide tracks and large wheels, with dramatic fender flares and air intakes that looked like nothing else on the road. The rear end was entirely redesigned to house the mid-mounted engine, with large intake ducts and a prominent rear wing. The only carryover panels from the standard Metro were the front windshield and the basic roof profile.
The 6R4's competition career was intense but brief. It debuted in the 1985 RAC Rally (driven by Tony Pond) and competed throughout the 1986 World Rally Championship season before the FIA banned Group B cars following fatal accidents in the Portuguese and Tour de Corse rallies. The 6R4 never had the chance to fully develop its potential, as the ban came just as the car was becoming competitive against the dominant Peugeot 205 T16 and Lancia Delta S4.
Approximately 200 Clubman (road-legal) examples were built to satisfy homologation requirements, alongside a smaller number of International-specification competition cars. The Clubman cars were genuine road-legal vehicles with windshield wipers, headlights, indicators, and basic interior trim, though they were clearly not intended for regular road use. The engine note was extraordinary — a naturally aspirated V6 screaming to high RPM in a car the size of a shopping cart.
Today, the 6R4 is one of the most iconic and valuable Group B homologation specials. Its connection to Williams F1, its remarkable engineering, and its association with the legendary Group B era make it a highlight of any collection. Values have risen dramatically as the collector market has embraced Group B cars, with well-preserved Clubman examples commanding serious money.
Authentication through the 6R4 registry is essential — each car has documented history. Clubman and International specs have very different values (International cars are worth significantly more). The V64V engine is complex but robust if properly maintained — overheating is the main concern. Gearbox and drivetrain components are specialist items with limited availability. Body panels are fiberglass/kevlar composite and can crack — sourcing replacements is difficult. Check for correct running gear, as some cars have been modified or parts scavenged for racing. Originality is critical for value. Many cars have active competition histories — racing provenance can add or subtract value depending on the buyer.
Approximately 200 Clubman (road-legal) examples built for FIA Group B homologation, plus approximately 20 International-specification competition cars. Developed by Williams Grand Prix Engineering. Built at the Austin Rover factory in Longbridge, Birmingham. The project was terminated when the FIA banned Group B in late 1986. The V64V engine later evolved into the Rover KV6 production engine.