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).

Yes. For software crashes, a forced restart (Hard Reset) can usually be done with a specific combination of physical buttons or by disconnecting the negative terminal of the 12V battery for 5 minutes to recover. We will send you these engineering operation manuals.

It depends on the situation. If the video inspection reveals significant mechanical faults or structural damage not disclosed in the inspection report, the deposit will be refunded 100% unconditionally; however, if the buyer defaults for subjective reasons (such as suddenly not liking the color or financial issues), the deposit will be retained as compensation for taking the vehicle off the market.