Stupid question regarding VIN numbers

[55 CDV Fan 82]

So in a previous post I discovered my car was #638th off the line for 1957 however my vin number is in the 3900 range (on the door).  Were the numbers consecutive for production (i.e. for each on they built they just assigned a number) or was it specific for that model?  Just curious because I'm trying to get a better understanding of the cars history

[Ralph Messina CLC 4937]

Tim,

If the 638 relates to the FW body number it is the 638th Coupe de Ville built. A Vin or serial number in the 3900 range indicates it was the 39xxth '57 Cadillac built. The body number is in order of build of that specific model. The VIN is in the sequence of all models built.

HTH,
Ralph