China's auto sector is booming, and Chinese auto makers are roaring to the top of the heap. Of the 30 members of the Auto/Truck-Original Equipment industry, ranked fifth out of 197 industries in Tuesday's IBD, a few are Chinese. Two companies aren't institutional-quality leaders, although that hasn't stopped their share prices from surging. Tongxin International (TXIC) and Sorl Auto Parts (SORL) make components for China's automakers. Tongxin, a