General/global VIN decode:
As you can see in the graphic above, the VIN is composed of six parts:
Make/Model: (Digits 1-3) This breaks out the vehicle's make, model, and manufacturer.
Vehicle Features: (Digits 4-8) These digits identify the various features of the specific model — trim specifications, driveline options, etc.
Verifying #: (Digit 9) Determined through a complex mathematical formula that relates to the other numbers in the VIN; used to verify that the VIN itself is not fake.
Model Year: (Digit 10) Represents the vehicle's model year, which is not to be confused with the year it was sold or delivered.
Assembly Plant: (Digit 11) An internal digit that shows where the car was built.
Sequence Of Model Production: (Digit 12-17) These digits indicate the order in which the vehicle left the assembly line. This is effectively the serial number.
Note: A VIN will never include the letters I, O, or Q because of their similarity to the numbers "1" and "0." BUt seriously, though: Who confuses a Q with a 0?
BMW VIN Decode:
Another one
Yet another one with more details:
Further read:
http://www.bimmerfest.com/forums/showthread.php?p=1231654