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).

Interior assessment is divided into three core areas: the driver's high-frequency contact area (steering wheel, gear shift, edge of the driver's seat), central control button area, and rear seats and ceiling. The natural sheen of leather surfaces (patina) is normal; however, any physical damage (such as leather tearing, fabric burn holes, or plastic breakage) will be classified as "structural interior damage" and clearly marked.

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."