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).

Because it's not a one-time transaction. Only by ensuring compliance checks, improving after-sales service, and providing parts can a good reputation be established, leading to repeat purchases and long-term cooperation.

Basic perception functions (like Adaptive Cruise Control ACC, Lane Keeping Assist LKA, and Automatic Emergency Braking AEB) rely on the vehicle's local radar and cameras, and can operate normally overseas. However, advanced features that heavily depend on high-precision maps and cloud data (like Navigation on Autopilot NOA and Full Self-Driving FSD) cannot be activated overseas.