Yes indeed, the VIN number corresponds to the line being produced at that plant and does not represent the actual number of AV built (in this case). ?The same factory in Mexico might have been building Tahoes or Suburbans (I am not sure what is produced there) at the same time which would share the same VIN code.
Here is the dirty - The VIN number as we know it has been standardized around 1983 as the result of a recommendation from the International Organization for Standardization (ISO). ?The current VIN system used world wide is comprised of 17 digits broken down in the following 3 sections:
First 3 = World Manufacturer Identifier (WMI)
Next 6 = Vehicle Descriptor Section (VDS)
Last 8 = Vehicle Identifier Section (VIS)
ISO recommends the 10 digit = YEAR
ISO recommends the 11 digit = FACTORY CODE
In the US this breakdown id done in 4 sections with the following breakdown:
First 3 digits = WMI
Next 5 digits = VDS
Next digit = Check digit, an arithmetic check for the other 16 characters. It may be numeric or the letter X.
10th Digit = YEAR (USUALLY)
11th Digit = FACTORY CODE (USUALLY)
Last 8 digits = VIS
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Doing it in this manner with the check digit in place allows the automotive industry to have a system by which they can verify legitimate VIN numbers from fake ones.
So as you can see the VIN can tell you who made, when it was made where it was made and in what sequence it travelled down the assembly line. ?As for actual production numbers. ?Well, depending on who the plant manager is, he/she will most likely have a complete cross referenced printout with each VIN number with the appropriate make and model breakdowns. ?
I have had the pleasure of seeing one of such books once (one of only 3 in existence) that allowed you to cross reference each Impala SS with their actuall prduction number. ?Those in SoCalSS (Souther California SS Club) know this well since it is how their member numbers are generated. ?Hope this helps. ?