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.

If insurance claims records are accessed, there will usually be notes like "the insured vehicle is fully responsible for hitting a fixed object" or "third-party liability insurance payment." We can roughly reconstruct the accident scene based on this and cross-verify the stress points on the vehicle's frame with paint thickness gauge data.

We will use a megohmmeter (insulation resistance tester) to measure the insulation resistance of the high-voltage bus. If the resistance value is below the national safety standard, it indicates a risk of leakage, and the vehicle will be deemed unqualified.