Audi may be about to write a new chapter into the history of the supercar. Its new R8 V12 TDi is, many argue, the world's first diesel-powered alternative to a Ferrari, Porsche, Lamborghini or AMG Benz. We've driven it - you can read our exclusive first drive by clicking here - and you can also watch Audi's video footage of the car below."Full throttle in this car makes you painfully aware of its driver's seat's lumbar support," writes Matt Saunders. "It is savagely fast, and deserves its future in production for that alone."