Sounds like a weird request, may I ask why?The local DMV needs to see an engraving, not a stamp.
I found this on the webz, not sure how accurate it is though.
"The VIN code for a Ford Flex is used to decode vehicle details and can be found in the following locations:
Inside frame or jamb of the driver-side front door
Dashboard on the driver’s side
Small aluminum I.D. tag found on the driver’s door
Stamped on the frame of the engine compartment just below the alternator
Right under where the seat would be located"