The Audi RS 6 sedan is the product of a joint effort between Audi and its tuning division, quattro GmbH, and will be the fastest Audi to reach U.S. shores thus far. It will offer a considerably higher level of performance than the S6 Avant introduced last year, largely because two turbochargers will be affixed to its 4.2-liter V8, resulting in 450 horsepower and 415 pound-feet of torque, slotting it in between the BMW M5 and the 2003 Mercedes-Benz E55 -- just where Audi wants to be. Quattro GmbH also made a number of chassis upgrades to manage all this power -- highlights include the debut of Dynamic Ride Control, which uses hydraulics to adjust damping during cornering, an even stiffer suspension than the S6's, a quicker steering ratio and a new brake system. Indeed, it's a good time to be a wealthy enthusiast.