A complete service history tells you more about a car than its mileage. In China, most maintenance is done at authorized (4S) dealers, and each visit is recorded in the brand's national database. First, ask the seller for the service booklet and maintenance invoices, then have your inspection agent call the brand's 4S network with the VIN to pull the full service record. This shows oil changes, major repairs, recall work and accident-related repairs. Second, check that the mileage recorded at each service visit increases logically. A gap between the database mileage and the dashboard reading is a red flag. Third, ask for the annual inspection (nianjian) records, which are mandatory in China and show whether the car passed emissions and safety checks on time. If the seller claims a full service history but the database shows no records, assume the car was maintained at small independent shops or neglected. Adjust your offer accordingly — plenty of used cars in China have documented histories.

Currently, in most developing countries, there is a severe lack of deep repair capabilities for the three electric systems. We recommend that B2B car dealers must have basic electrical insulation testing capabilities.

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.