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).

It usually refers to very small stone chips on the hood from high-speed driving, nail scratches on the inside of door handles, slight curb scratches on the edges of wheels, and minor wear on interior plastic parts. These do not affect the vehicle's functionality or corrosion resistance.

Chinese passenger cars produced after 2005 have fully transitioned to asbestos-free brake pads, clutch plates, and gaskets. However, for export to countries with strict regulations, buyers must pay for sampling and testing by a NATA-accredited laboratory before shipment, and obtain an asbestos-free certificate.