Something is probably funky with the two VINS, but I can tell you the
square drive sheetmetal screws were installed by a Canadian...square
drive or "Robertson" screws as they are called are very popular in
Canada.  According to Wikipedia 85% of screws sold in Canada have
Robertson heads....that seems a little high to me but they sure are
better than Phillips head or plain slotted screws....

http://en.wikipedia.org/wiki/Robertson_screw
http://www.mysteriesofcanada.com/Ontario/robertson_screws.htm

>there is another VIN, (different VIN#, with no "ZZZ" in it)
>directly behind it on the dash - SCREWED ON with square drive
>sheetmetal screws
>(which i have never seen done, ever)  and the screwed on VIN is the one that
>matches the driver's doorjamb VIN/ID sticker,