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.

It is extremely dangerous and usually not allowed. This can easily trigger the anti-money laundering (AML) controls of China's foreign exchange administration. The remittance account title must closely match the contract buyer and the bill of lading consignee. If payment on behalf is necessary, a legally binding "Tripartite Payment Agreement" must be provided in advance and undergo compliance review by our finance department.