The new Audi RS6 has two rivals; the BMW M5 Touring, and the Mercedes E63 AMG estate. The competition just gained a huge advantage.Audi confirmed today that the 572bhp, twin-turbo V10 RS6 will cost £76,625 – £9,445 more than the M5, and £7k over the E63. However, the RS6 is the most powerful production Audi ever and comes fully equipped with every essential gadget as standard, so it could well justify the premium.For your £77k, you get parking sensors, 20-inch alloys, leather interior including heated front and rear seats, 6-disc CD changer, sat-nav, DAB radio and BOSE sound system. Not to forget the extra 70bhp the RS6 has over the BMW, and 46bhp over the Merc. We've already had a go behind the wheel of Audi's latest RS model, and it certainly didn't disappoint.