MOSCOW — Audi must have figured cash-rich Russia is a key market for its new RS6 sedan. Why else would the German automaker choose the 2008 Moscow Auto Show as the venue of choice to debut its new executive muscle car?The RS6 is already garnering much of the early press attention from the show, which opens August 28 and runs through September 1. Audi also plans to display the car at the 2008 Paris Auto Show in early October, although the company has no immediate plans to sell the RS6 in the U.S.Powering the RS6 is a twin-turbo 5.0-liter V10 that makes 572 horsepower and 479 pound-feet of torque. The engine drives all four wheels through a six-speed automatic gearbox. Performance specs include a 0-60-mph time of less than 4.5 seconds and a top speed of 174 mph.The car goes on sale in Germany with a starting price of nearly $155,000. Russian sales should commence shortly after that.What this means to you: That's a lot of rubles — but it's also a lot of car. — Paul Lienert & Tai Adelaja, Correspondents