Taking on the boss here, but he seems a fair guy.
Logan...Not sure what you're saying "nope" to, but if I read a 2MEHM75V83X VIN prefix from the dash of a CV or GM, I'd buy that car as a "one-of-a-kind" production line goof, (ala miss-minted coins) or, seize it as a counterfit VIN.
As for the production suffix, the MMs rolled out with in the low 60000 on 13 May, 02. Could two cars share an identical suffix? You bet. I'm sure there is a GM or CV out there with the same last six digits as my MM, maybe even an Impala SS too, but not with a matching prefix. The prefix is unique to the MM, period. Maybe the VIN isn't an official "build" number, but it's a hint and maybe what the Capt. was looking for?
I respectfully agree that production line "broadcast" sheets have their own sequential control numbers that some could say, is a "build" number. And, I respectfully agree that brodcast sheets are shared across the spectrum of platforms at the St. Thomas production line, so, sequential sheets may control different cars. But, broadcast sheets are internal control, and as the car moves down the line, a sequential VIN is created and attached.
Now, I don't like to "presume" things, but truthfully, I don't really know. So, I presume that VINs become assigned in sequence because the cars are produced in sequence. Logical, yes, but I can't say for sure. Of course, LM may have made an effort to insure a random suffix, but that rubs against the grain of efficiency in a production line process too, so, is it just as reasonable to presume random assignment?
Nope.