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).

Start with the paperwork: the vehicle registration certificate lists every ownership transfer, and the service book plus dealer maintenance records help confirm mileage. For digital verification, ask the seller for a live video walkaround plus a diagnostic scan report showing the ECU-recorded mileage, which is hard to manipulate. For EVs, request a battery state-of-health (SOH) report — it reveals real usage patterns far better than the odometer. Finally, a pre-shipment inspection by a third party should include structural checks (pillars, chassis rails) to rule out accident repairs. Build "no major accident, no flood or fire damage" into your purchase contract with a refund clause if the inspection contradicts it.

Always rely on the original factory network data from the 4S store. Third-party platforms may have delays or errors when capturing data (such as incorrect VIN entry). In case of a conflict, we rely on physical verification of the actual vehicle to resolve the data discrepancies.