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).

Vehicles sold domestically in China only have the "Environmental Information List" and the "Vehicle Qualification Certificate," which are not the COC of the European system. We will provide a notarized English translation of the Chinese qualification certificate. If local customs strictly require the original European COC, the vehicle will not be able to clear customs.

To prevent intermittent failures due to aging of the resistance wire, we will start the engine and set the seat heating/ventilation to maximum for at least 5 minutes, confirming significant temperature changes or airflow output in the cushion and backrest using an infrared thermometer or body sensor.