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.

For older vehicles or those used in high temperature and humidity areas, we will focus on opening the hood to check if the insulation of the wiring harness in the high-temperature area of the engine compartment is cracked or brittle, to identify potential short circuit risks that could lead to spontaneous combustion.

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.