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.

Many car owners do not have their first maintenance done at authorized dealerships, leading to gaps in early data. In such cases, we do not blindly trust the odometer; instead, we analyze the tire production dates and wear levels, as well as the depth of grooves on the brake disc edges, using the "gold standard" of physical wear to infer the intensity of early use.