Germans automakers - Audi, BMW, Mercedes - Porsche - continue to dominate China's 1.8 million million per annum luxury market. They take just under 80% of all premium sales. But Cadillac and Lincoln are gaining traction as fresh alternatives to the ubiquitous German marques. GM produces Cadillac XT5s, ATSs and other sedans at a new billion-dollar plant in Shanghai with its Chinese partner the Shanghai Automotive Industry Corporation. Lincoln imports its full set of offerings