Audi's gonna do it. According to a German report, they're putting a race-derived 6.0-liter V12 TDI in the Q7 SUV for 2008. The street version of the V12 TDI will be the most powerful passenger car diesel in the world, with -- get this -- 500 horsepower and a staggering 720 lb ft of torque on tap. And it doesn't end there. According to the same report, the monster diesel will find its way into the next A8 sedan, due in 2010.