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 "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.

Unless the previous owner retained the original parts and provided them to us, we usually keep the existing modifications and clearly state in the report "includes non-original modifications." Since the standards for illegal modifications vary by country, buyers should assess whether these modifications can legally pass inspection in their destination country.