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).

Interior wear is harder to fake than an odometer and often reveals true usage better than any document. Focus on high-contact points the seller rarely restores. The driver's seat bolster shows creasing and cracking by 80,000-100,000 km even with covers. Steering wheel leather polishes smooth and darkens with hand oils; a shiny wheel with low claimed mileage is a red flag. Pedal rubbers wear through at similar rates — check accelerator, brake, and clutch depth. Second-row wear patterns tell you how the car was used: heavy child-seat indentations suggest family use (usually gentler), while uniform rear wear with clean front suggests commercial or ride-hailing duty. Check seat rails for rust (indicates water ingress) and look under floor mats for moisture staining or musty smell — flood cars often hide it there. Also examine the infotainment and instrument cluster: Chinese EVs log usage data internally, and a dealer diagnostic readout can cross-check driving hours against mileage. Request close-up, well-lit photos of these specific points during your live video inspection rather than relying on the seller's gallery.

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.