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).

We use a calibrated high-precision paint thickness gauge to take multiple measurements on at least 13 metal surfaces of the entire vehicle. The original paint thickness of mainstream Chinese models typically ranges from 90μm to 150μm. If any area exceeds 200μm or even reaches over 500μm, we will directly conclude that the area has undergone bodywork and filler repair.

Temperature differences during sea transport can easily trigger the tire pressure warning. After inflating the tires to the standard pressure (usually 2.5 Bar), most vehicles will automatically clear the warning after driving a few kilometers; some models require manually clicking "Tire Pressure Reset" in the "Vehicle Settings" on the central screen.