Oh, the perils of endorsement deals. No wonder some brands just shy away completely. You just don't know what's under that celebrity stone. Take Hyundai's endorsement deal with Chinese swimming sensation and Olympic gold medalist Sun Yang. Great snag for Hyundai, because he's a superstar in China. Except, um, last week he was taken into custody after a traffic accident involving a Porsche SUV. He was driving the Porsche SUV.