No subway in Jeju — getting around without a car as a tourist-turned-resident

Spent a month in Jeju before realizing there's no metro and buses can be slow. The 660/670 airport buses and the Blue/Green local buses do cover a lot — use the Kakao Map or Naver Map app, not Google (transit routing is poor here). T-money card works on buses. For the coast and Olle trails, honestly renting a car or even a scooter is the norm. Anyone living car-free long term in Jeju, how do you manage groceries?