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.

Many car owners do not have their first maintenance done at authorized dealerships, leading to gaps in early data. In such cases, we do not blindly trust the odometer; instead, we analyze the tire production dates and wear levels, as well as the depth of grooves on the brake disc edges, using the "gold standard" of physical wear to infer the intensity of early use.

All vehicles on the lift must be inspected. We will provide high-definition close-up photos of the chassis directly below, suspension components, and the mid to rear section of the exhaust. We will honestly show any minor surface rust (a common phenomenon in cast iron); if we find bent longitudinal beams or extensive through-corrosion, the vehicle will be scrapped and not exported.