Thanks tequila.
Couple of latest posts on facebook regarding where they are getting the info from - the door plate rather than title or registration
This was our experience except our registration did not show GVWR. The Banjercito agent asked for a cell phone photo of the inside of my driver door where GVWR is printed. I hope this does not become their official protocol or this loophole will not work.
Same with us. They came outside and looked and photographed the sticker on our door which has our GVWR on it. Our registration and title did not have any weights on it at all, so maybe if it did it would have helped.