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).

The "usage type" section on the vehicle registration certificate has legal validity. Any vehicle that changes from "commercial" to "non-commercial" has a usage intensity far exceeding that of personal vehicles, and we will label these prominently. Such vehicles are usually cheaper but have more severe mechanical wear.

Pure electric vehicles are classified as Class 9 Dangerous Goods due to their large lithium batteries, leading to strict shipping regulations. Shipping companies have high requirements for the loading position and fire isolation measures for dangerous goods, and some roll-on/roll-off ships refuse to accept used EVs. As a result, EVs often require more expensive special container shipping and incur additional handling fees for hazardous materials.