Rocker Bryan Adams was on hand to help Audi launch the world’s first diesel supercar, the R8 V12 TDi concept, at the Detroit motor show yesterday. Audi’s huge stand looked like a TV set. The company even hired a US television presenter to chair proceedings - his job to nurse the terrified, sweating German execs through their scripted routines, all read from autocues. Eventually the R8 diesel rolled onto the stage through a cloud of smoke, and Adams burst into “The Only Thing That Looks Good On Me Is You”. Hilarious. But beyond all the pomp and circumstance the car looked great in the metal, wider and more aggressive than the petrol R8 we know and love. And, of course, there’s that huge 500bhp, 737lb ft torque V12 diesel cleverly packaged in the rear. Inside, there’s now a switch for Race, Dynamic and Sport settings to firm up the ride and sharpen throttle response. The instrument backlighting changes colour depending on which mode is selected, and in Race mode the sat-nav system shows a map of the circuit you're lapping and gives a data read out on your lap times. The strong feeling on the show floor is that this diesel R8 is definitely coming, but reliable sources suggested that the production version is more likely to use a V8 oil-burner, not a V12. It seems the V12’s 737lb ft torque really is too much and, among other issues, it could be too expensive to engineer a strong enough paddle-shift ‘box – a necessity for the R8's target audience. Nothing is definite, but if the reaction at Detroit is anything to go by, everyone is looking forward to driving the diesel R8 whether it's a few cylinders short of the concept or not.