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.

We will never perform blind deep disassembly unless there are clear severe fault codes or extreme noises. The sealing of the engine and transmission is crucial, and compromising the factory seals to investigate non-existent issues is unprofessional. We rely on data flow and external acoustic and fluid analysis to make judgments.

If the car has been maintained at an authorized dealer, we can extract the desensitized official maintenance history (including entry time, mileage, and maintenance items) through a paid third-party data provider and provide it to you. If some year records are missing, we will honestly inform you that the "records are incomplete."