We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

For B2B large customer orders, a "sampling + full inspection" dual regulation is adopted. Core parameters (no major accidents, no water damage or fire) are subject to 100% inspection per vehicle; appearance and condition are uniformly graded (e.g., uniformly purchasing Grade A), and panoramic images of all vehicles in the batch along with a core indicators comparison list are provided before shipment.

Unauthorized personnel are prohibited from entering and taking photos inside the roll-on/roll-off ship, but we will provide photos of the vehicles parked in the loading area with the ship in the background. The bill of lading marked "Shipped on board" with the date is the most essential legal proof of loading.