The luxury street is jammed with people waiting to drive away marquees such as Porsche Cayenne, BMW X1, Audi A8 and Mercedes S500, because carmakers are trailing speeding demand by up to six months. Premium car sales in the country grew 70%, or at more than double the rate of the industry’s best expectation in 2010 to 15,000 vehicles, throwing carmaker’s supply chain out of gear. Manufacturers are ramping…