Once the car system (especially in a closed ecosystem) undergoes a major version upgrade, its bootloader is usually locked, preventing downgrades. If this happens, there is basically no solution in an overseas environment. Therefore, we strongly warn: do not blindly insert a USB drive to upgrade while offline.

Vehicles sold domestically in China only have the "Environmental Information List" and the "Vehicle Qualification Certificate," which are not the COC of the European system. We will provide a notarized English translation of the Chinese qualification certificate. If local customs strictly require the original European COC, the vehicle will not be able to clear customs.

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.