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).

4S dealership records are directly connected to the manufacturer's database, making the data hard to tamper with and the most reliable, with original parts guaranteed; third-party repair shops usually are not connected, making their data unverifiable. Therefore, we only consider the connected records from 4S dealerships as valid historical documentation.

It depends on the specific brand and model. Some brands (like BYD and MG) have native multilingual systems that can switch to English directly; however, some models designed for the Chinese domestic market only have a Chinese interface. For systems that only have Chinese, we can assist with compliant system flashing (installing international firmware) or adding modules that support Apple CarPlay/Android Auto, so you can use Google Maps. The details page will clearly indicate the language status of each vehicle's system.