We maintain an absolute skeptical attitude. In addition to regular visual inspections, we focus on checking for sediment accumulation around the sunroof drainage channels and look for water stains under the A-pillar trim and front floor mats. This is the only effective physical evidence to determine if the sunroof drainage holes are blocked, leading to hidden leaks.

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.

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).