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.

Testing is mandatory. Troubleshooting electrical devices in the car is part of the standard procedure. We will test the window lift motors, mirror folding, air conditioning compressor and fan, electric seat tracks, etc. Any stuttering or failure of electronic components will be recorded.

We thoroughly rule them out by checking if the cabin wiring harness is melted, if the seat belts have water stains or mold, if there is unusual rust or debris in the seat tracks and cigarette lighter, and by verifying with the insurance company for any "total loss claims." These two types of cars are an absolute sales ban for us.