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 will proactively provide a third-party inspection report (such as from Check Doctor), support customers in re-inspection at the store, and promise "return of major accident vehicles."

We will directly check the registration certificate (the big green book) and count the number of changes.