VINs: The Encoding Stamped Into Steel

An exploration of Vehicle Identification Numbers as an encoding standard (ISO 3779), where VINs pack manufacturing data into 17 characters covering world manufacturer identifier, vehicle descriptor section, check digit, model year, assembly plant, and sequential production number. Design choices include omitting O/I/Q to prevent transcription errors and excluding trim, color, and title status since these change over a vehicle’s lifetime. At CarGurus, VINs serve as immutable unique identifiers connecting listings to historical data, trim inference, and title/damage records from state DMVs and third-party aggregators.