When sourcing used buses, prioritize the engine condition and mileage, as these directly impact operational costs. For the Indonesian climate, ensure the Air Conditioning (AC) system is high-capacity and fully functional. Verify the chassis integrity for signs of rust or structural repairs, and confirm the seating capacity aligns with local transport regulations (e.g., 25-seater for medium buses or 50+ for big buses). Additionally, check if the emission standards (Euro 2/3/4) meet the current Indonesian environmental requirements for vehicle registration.