In making it, the stylists substituted most of the standard R8's carbonfibre for aluminium, and added bumper- and sill-extensions in the same polished alloy, as well as a proper underbody air diffuser. The result looks threatening and aggressive, like the kind of car that devours roads, and whatever may be on them, without so much as a change of gear.
Which is exactly as it should be, since this particular R8 has the wherewithal to do exactly that. Powered by a Hungarian-built twin-turbodiesel V12 (the same, but for a dry sump, that you'll find in the new Q7 V12), this car will do 62mph in 4.2sec, 100mph in less than 10sec, and more than 190mph flat out.
More phenomenal than that is its in-gear pulling power, which is the truest measure of everyday performance on the road. 738lb ft is almost as much twist as a BMW M6 and a Ferrari F430 muster between them. In a car that should weigh just 150kg more than a V8-powered R8 in road-going guise, or about 1750kg. Doesn't take a genius to work out why Audi has been so excited about performance diesels, does it?
This car will also do an average 25mpg, of course, and emits about 250g/km of CO2 – which are figures usually associated with hot hatches, and never before with near-200mph supercars.
So does it feel as savagely fast as the figures suggest? Well, on the back of this test drive it's difficult to be definitive. Audi's test route was short, and its concern for the one working prototype of this car considerable. We weren't allowed to do more than 35mph, proper cornering was forbidden, and full bore starts were out too.
That effectively reduced us to a couple of runs around what amounted to little more than car park access roads. So I can report that this R8 appears to steer and ride much like a standard one (ie very nicely indeed). It's got Audi's excellent magnaride adjustable dampers, which add a couple of new dimensions to its ride and handling repertoire.
And yes, its certainly quick – quicker even than anybody really knows yet. I risked a knuckle-rapping by giving the car full throttle in 3rd, from 25mph and 1000rpm; it mugged the tarmac and began hurtling at the horizon with an urgency that made me painfully aware of the driver’s seat’s lumbar support. There was no wheelspin, no turbo lag. I only felt the full savagery for a couple of seconds, but that was enough to convince me that this car deserves a future in production.
And here comes the really mad part; apparently, that was literally just half the story. Audi had to fit an A4 gearbox into this car, as it doesn't currently have one small enough to fit, but man enough to handle 1000 newton meters. As a result, the car's V12 is only running at half-wick; 369lb ft. Believe me, then, when I state that the road car will be quicker than, and yet almost wholly unlike, any sports car you've ever driven.
Should I buy one?
Well, you'll probably have to wait until 2010. That's as soon as Audi is likely to be able to put the R8 TDi into production, probably with a new transverse 7-speed DSG gearbox.
And you'll have to have quite a particular taste in fast cars. You'll have to like them as frugal and low-CO2 as possible; interesting to listen to, but not at all sonorous; riveting to drive, without being quite as involving as a high-revving petrol; and you'll have to be into massive real world performance delivered in an easily-accessed, totally undramatic way.
If you run a Porsche 911 GT3 then, you'll probably hate this car, and would be well advised to steer clear. But if you drive an AMG Merc, on the other hand – and there are plenty of those on the road these days – this R8 could be right up your alley, heater plugs and all.
Audi R8 V12 TDi Le Mans
Price na; 0-62mph 4.2sec; Top speed 202mph; Economy 25mpg; CO2 250g/km; Kerb weight 1750kg; Engine V12, 5934cc, turbodiesel; Power 493bhp; Torque 738lb ft; Gearbox 6-speed manual