When BMW was looking for a place to roll out its new top-of-the-range 7 Series model, one country immediately came to mind: Russia. Demand for luxury autos has been soaring there — BMW's Russian sales have quadrupled in the past five years and were up 54% last year alone. So the German automaker threw a splashy party in Moscow on July 8, unveiling its revamped model inside a 40-ft.-high (12 m) acrylic-and-steel hourglass that it erected on Red Square itself. The show "reflects the confidence that the BMW Group has in this country's potential," gushed Christian Kremer, the company's managing director...