Due to legal restrictions preventing unregistered vehicles from high-speed driving on public roads in China, most of our dynamic tests are conducted in a closed area (with a maximum speed of around 60 km/h). This is sufficient to test for suspension noise and low gear smoothness, but it cannot simulate high-speed wind noise and tire balance vibrations at 120 km/h.

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.