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).

All vehicles on the lift must be inspected. We will provide high-definition close-up photos of the chassis directly below, suspension components, and the mid to rear section of the exhaust. We will honestly show any minor surface rust (a common phenomenon in cast iron); if we find bent longitudinal beams or extensive through-corrosion, the vehicle will be scrapped and not exported.

4S dealership records are directly connected to the manufacturer's database, making the data hard to tamper with and the most reliable, with original parts guaranteed; third-party repair shops usually are not connected, making their data unverifiable. Therefore, we only consider the connected records from 4S dealerships as valid historical documentation.