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).

Our legal red line is that the amounts on the China Customs declaration, export license, commercial invoice, and bank receipt must be consistent across all four documents. We firmly refuse to engage in the illegal act of issuing "false low-value invoices" to assist buyers in evading customs duties in the destination country.

For older vehicles or those used in high temperature and humidity areas, we will focus on opening the hood to check if the insulation of the wiring harness in the high-temperature area of the engine compartment is cracked or brittle, to identify potential short circuit risks that could lead to spontaneous combustion.