Coupon Tree Rentcar is a rental car company in Yongdam Sam-dong, Jeju City. Vehicles are kept clean and staff are friendly. Pickup is at the airport rental car house Zone 4, at the number 5 on the floor, where you take a shuttle to the company. After returning the car, you are dropped off at the airport departure level, and the shuttle ride takes about 15 minutes because the company is some distance from the airport.