Classified ad of the week: Metro 6R4

There is only one acceptable Austin Metro to lust after. And those equipped with eyes are looking at it - the 6R4 (6 stands for number of cylinders, R for rear-engined and 4 for four-wheel drive).

That's largely because it's not really an Austin Metro. It's a racecar. And it visits us from the Group B rally dimension - an anomalistic departure from motorsport's heavy-handed regulations, where cars subjugated the natural world under a curtain of smoke, sound, and improbable clods of power.

But the FIA did impose one rule we approve of - the cars had to be homologated, to the tune of 200 examples. Which meant ordinary non-racey types got to own and drive their very own group B hoons on the road whenever they wanted. Which, frankly, is insanity. And it means that some occasionally trickle onto the second-hand market, rather like this one.

First, some history. Brainchild of the Austin Rover Sport Chief, John Davenport and brought to fruition by Williams F1 engineers, the 6R4's permanent four-wheel drive system was inspired by Audi's revolutionary setup. But the company needed something offensively powerful to shunt it around. Not, then, the original car's gently pathetic A-series engine (an early derivative of which was used in the original Mini, fact fans). So it slotted a 3.0-litre 90-degree V6 in the boot, which had twin-cam heads modeled on Cosworth's Formula F1 DFV V8 engine. That means, in competition tune, it pushes out 394bhp. For reasons we can only assume pertain to sustaining human life, the £40,000 homologation Clubman version was detuned to around 250bhp.

But this particular Clubman, which has just 4,000 miles on the clock, seems to have been fitted with said 394bhp engine (though the owner's offering the original engine through "separate negotiation"). Despite the power bump, it's actually lead a pretty cosseted existence, and has only just resurfaced after many years in storage. J172 JRN was used as demonstrator and promotional mule - it was even a course car on the 1991 Pendragon Stages. Consequently, it wasn't registered until August 20 1991, and it's barely been used since. We can't vouch for its condition, but it looks a damn site less battle scared than the car Prodrive used in the 1986 RAC Rally that we saw last week...

Now the good bit: the reckoning. It's up for auction, but the seller estimates the most absurd car with a tax disc will cost you in the region of £70. Fresh MoT included, but you'll have to pay another £15,000 on top to get the original engine, just in case you want a to make a nice coffee table. Find out more here

Any takers from the topgear.commer ranks?