The "usage type" section on the vehicle registration certificate has legal validity. Any vehicle that changes from "commercial" to "non-commercial" has a usage intensity far exceeding that of personal vehicles, and we will label these prominently. Such vehicles are usually cheaper but have more severe mechanical wear.

The nameplate date is the absolute time when the vehicle leaves the factory; the registration date is when the vehicle is registered with the traffic management department after sale. The difference represents the time the vehicle spent in the dealer's warehouse or logistics. If the time difference exceeds 6-8 months, the vehicle is considered a "stock vehicle," and we pay special attention to the natural aging of its rubber components.

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).