Hyundai Motor and affiliate Kia Motors aim to boost global vehicle sales by 6 per cent this year to a combined 7 million vehicles, which would mark a slowdown for a duo that has enjoyed double-digit sales rises in recent years. The South Korean automakers, which together rank fifth in global car sales, are unable to keep up with demand because of stretched production capacity. But they have refrained from boosting capacity sharply, instead focusing on improving product quality and profits. Bigger rival Toyota Motor last month forecast a 20 per cent jump in 2012 sales to a record 8.48 million vehicles, as it is recovering from output losses caused by natural disasters in Japan and Thailand last year. \"We will strengthen quality management we have continuously pursued,\" Chung Mong-koo, chairman of Hyundai and Kia\'s parent group, said yesterday in his annual speech to employees. Article continues below The 73-year-old Chung has headed Hyundai Motor Group since 2000 when he led auto-related firms out of the parent Hyundai Group, then South Korea\'s biggest conglomerate marred by financial troubles and a bitter family feud. The son of Hyundai\'s founder is credited with transforming the once maker of cheap, poor-quality vehicles into a stellar performer, especially during the global economic downturn.