Stew Hansen Hyundai in Des Moines feature world-class service to help keep you on the road. Our Iowa Hyundai customers that need an oil change, warranty service find our service center convenient and dependable. Stew Hansen Hyundai in Des Moines feature world-class service to help keep you on the road. Our Iowa Hyundai customers that need an oil change, warranty service find our service center convenient and dependable.