From what I know, if an older BMW was manufactured, say in 12/72 and was sold that month, then it is a 72, but if it was sold in the following year even if it the first day of January, then it would have been a 73. So, if you have a 74 car in California, and get the certificate from BMW showing it to be manufactured in 73, you can take that into DMV and have them change year on the title and get away from smogging it!!!!!