family engine number --- 2000 Jetta

Hi... I recently moved to the States from Ontario, Canada and am trying
to import my Jetta in to the country. VW is asking to supply them with
the car's VIN # (no problem) and the "family engine number", which they
say is 11 digits long (letters and numbers). I have no clue where this
number is. I have even taken it in to a local dealer and the kid that
helped me there showed me where the motor number was but not the
"family engine number" which apparently are two different numbers. I
have checked the hood, there is nothing on it. VW also told me to
check behind the headlight, but I don't really see anything. If anyone
out there can give me some clues as to where this "family engine
number" is, I would be forever greatful. Thanks!