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).

Most models adjust through the central control screen menu, while a few models (like some BYD or MG) retain physical levers or paddles on the center console or steering wheel. We will check if the drag feel when the system engages is linearly normal.

China has a large number of luxury cars and a fast turnover rate. For luxury cars of the same year and mileage, the FOB offshore price in the Chinese market usually still has a 10%-15% arbitrage opportunity after deducting shipping costs, especially for models with high depreciation rates.