When sourcing used cars, the Vehicle Identification Number (VIN) is the most critical starting point to verify the car's history. Buyers must demand a comprehensive inspection report covering the engine, transmission, chassis, and electronic systems. Ensure the mileage is authentic by cross-referencing maintenance records. For electric vehicles (EVs), prioritize Battery Health (SOH) reports, as the battery accounts for a significant portion of the vehicle's value. It is highly recommended to use third-party inspection services (like SGS or TUV) to verify that the vehicle has no history of major accidents, fire damage, or water immersion.