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 platform has strict internal outbound inspections. If buyers need, we can assist you in commissioning an independent third-party evaluation agency (such as Cha Doctor, Dongche Di official testing, etc.) for re-inspection, with costs borne by the buyer. An independent report can provide more credibility for your local resale.

The headliner is considered an "irreversible interior component." If the edges are delaminated or there are deep, hard-to-clean dark water stains, it will directly lead to a downgrade in the interior grade, even if it does not affect driving. We will not use pins or low-quality glue for cosmetic repairs.