Both the BMW M5 and Audi RS6 you're about to see battle it out on the drag strip have been heavily modified. The M5 has received an AFE air intake and carbon scoops, AMS downpipes, H&R dampers, and BurgerMotorSports piggyback, as well as a host of other upgrades, and the hi-po sedan is now putting down 700 horsepower. The Audi RS6 has a remapped ECU courtesy of tmchiptuning.com, giving the potent wagon 690 horses.

With output around the same, this is a test of the cars' torque, transmission and aerodynamics. The M5 is also marginally lighter than the Avant. On paper it seems a pretty fair fight. It's also a rolling start, so the Audi's AWD can't play too big a part here. Place your bets, and click the video.