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).

It does not affect basic driving and regular speed cruise, but it will trigger a fault alert for advanced driver assistance on the dashboard. The LiDAR assembly is extremely expensive, so we focus on checking the integrity of the glass cover with a strong flashlight during inspections.

Maintain objective expectations. Vehicles over 5 years old inevitably show signs of decreased paint gloss, slight aging of rubber seals, irreversible patina on interiors, and surface rust on chassis components. As long as core structure and mechanical failures are not involved, these are normal depreciation characteristics over time.