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.

The nameplate date is the absolute time when the vehicle leaves the factory; the registration date is when the vehicle is registered with the traffic management department after sale. The difference represents the time the vehicle spent in the dealer's warehouse or logistics. If the time difference exceeds 6-8 months, the vehicle is considered a "stock vehicle," and we pay special attention to the natural aging of its rubber components.

We will carefully check if the chassis number on the windshield, chassis, and door frame matches.