Request a live video call during the test drive rather than a pre-recorded one. Cold start first: listen for rattling or metal scraping in the first seconds — possible timing chain or hydraulic lifter issues. During acceleration, a whining from the gearbox area can mean bearing wear; hesitation or jerking in an automatic suggests transmission problems. Braking: the pedal should feel firm, not spongy, and the car must not pull to one side. Turn the wheel fully in both directions and listen for clicking — a classic CV joint fault. Insist on a highway segment too: vibrations above 100 km/h often point to unbalanced wheels or bent rims. Ask the driver to film the dashboard throughout — warning lights that flicker on briefly are still faults that OBD will record.

To prevent intermittent failures due to aging of the resistance wire, we will start the engine and set the seat heating/ventilation to maximum for at least 5 minutes, confirming significant temperature changes or airflow output in the cushion and backrest using an infrared thermometer or body sensor.

We use a calibrated high-precision paint thickness gauge to take multiple measurements on at least 13 metal surfaces of the entire vehicle. The original paint thickness of mainstream Chinese models typically ranges from 90μm to 150μm. If any area exceeds 200μm or even reaches over 500μm, we will directly conclude that the area has undergone bodywork and filler repair.