Vehicle Identification Numbers (VIN codes)/Model year
Prior to 1980 the model year was in the 6th position. In 1980 the model year is encoded in position 10 of North American VIN codes. Besides the three letters that are not allowed in the VIN itself (I, O and Q), the letters U and Z and the digit 0 are not used for the year code. Note that the year code can be the calendar year in which a vehicle is built, or a model or type year allocated by the manufacturer. The year 1980 was encoded by some manufacturers, especially General Motors and Chrysler, as "A" (since the 17-digit VIN wasn't mandatory until 1981, and the "A" or zero was in the manufacturer's pre-1981 placement in the VIN), yet Ford and AMC still used a zero for 1980. Subsequent years increment through the allowed letters, so that "Y" represents the year 2000. 2001 through 2009 are encoded as the digits 1 through 9, and subsequent years are encoded as "A", "B", "C", etc.