The market share of Hyundai Motor Co. and its affiliate Kia Motors Corp. in the United States reached a record high in July, fueled by brisk demand for popular models, industry sources said Monday. Hyundai and Kia, the flagships of Hyundai Motor Group, sold a combined 72,440 passenger cars last month for a market share of 14.6 percent, up 0.2 percentage point from 14.4 percent in June, findings by the local automotive industry showed.