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.

Under FOB or CIF terms, all risks before crossing the ship's rail are borne by the seller (us). For minor scratches, we will provide a price discount based on the damage assessment; for serious damage, we will immediately terminate the vehicle delivery, refund the full amount, or replace it with a vehicle of equivalent configuration.