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).

The method to deceive the dashboard warning light is to install a resistor. Our technicians will deeply read the real-time resistance values from the airbag control module (SRS Module) data stream and check for any non-factory stitching or adhesive marks on the steering wheel/passenger panel to uncover the disguise.

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.