South Korea\'s five automakers, led by Hyundai Motor Co., said Monday their sales increased 9.9 percent on-year in July thanks mainly to overall gains in demand at home and abroad.Their combined sales came to 626,060 units last month, compared with the 570,062 vehicles a year earlier. Sales in overseas markets gained 10.9 percent on-year to 498,823 units last month while domestic shipments rose 6.2 percent to 127,237 units.