We maintain an absolute skeptical attitude. In addition to regular visual inspections, we focus on checking for sediment accumulation around the sunroof drainage channels and look for water stains under the A-pillar trim and front floor mats. This is the only effective physical evidence to determine if the sunroof drainage holes are blocked, leading to hidden leaks.

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.

This involves personal privacy, and we have no right or ability to retrieve personal driving violation records from the traffic police system. We can only infer if there was aggressive driving by checking if the engine has been reprogrammed with a higher-level ECU (stage 1/2) or if the transmission has a history of severe overheating.