A vehicle identification number is created by combining a certain configuration of letters and numbers from the auto manufacturer and the U.S. Department of Transportation. The 17-digit serial number includes the World Manufacturer Identity numbers from the DOT and the NHTSA and the unique numbering system stamped by auto manufacturers.
The WMI is the first three numbers and letters of a VIN. The first letter indicates the vehicle's nation of origin. For example, cars made in the United States have 1, 4 or 5 for the first-digit numbers, while vehicles from Japan are assigned the letter "J." The second letter identifies the manufacturer, such as "A" for Audi or "G" for General Motors. The third letter or number, when combined with the first two identifiers, is an identification of the vehicle's manufacturing division or type. A Cadillac passenger car may have "1G6" as its WMI, while a Chevrolet may have "1GC" as its three-digit WMI.
Positions four through eight describe the type of vehicle to detail, such as body type, trailer type, length in feet and number of axles. Position nine is a check digit that identifies an invalid VIN. Positions 10 through 17 make up the vehicle identifier section, with position 10 indicating the model year, position 11 telling the location of the manufacturing plant that affixes the VIN, and positions 12 to 17 the sequential production number or the numbers assigned to the cars on the assembly line.
The Department of Motor Vehicle verifies the format of the VIN before issuing a state title. If the format is incorrect, the DMV returns the documentation to the dealer and the dealer sends it back to the manufacturer for correction.