Pure electric vehicles are classified as Class 9 Dangerous Goods due to their large lithium batteries, leading to strict shipping regulations. Shipping companies have high requirements for the loading position and fire isolation measures for dangerous goods, and some roll-on/roll-off ships refuse to accept used EVs. As a result, EVs often require more expensive special container shipping and incur additional handling fees for hazardous materials.

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 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.