Here is what Mexico Mike was just told. i ma still working on it from my end.
For myself, I will definetely try to do my permit on line so I do not get blindsided at the border. my registration shows both GVW & net. I am going to see if the insurance agent can print me out a copy with the GVW left off. Here in BC insurance & registration documents are the same.
Reynosa, TAM. Interviewed Banjercito officials at two crossings. It is official. Unless your title or registration shows your vehicle is a motorhome, you cannot get a temporary import permit (some call it a TIP) for a car/truck with a GVWR > 7,716 pounds. No if's and's or but's. I also got the same story from Banjercito officials in Mexico City, but wanted to make sure this was the truth on the border, too.
However, if your state's title does not show GVWR, but only Vehicle weight, an official smiled and said that was all she would see. So there IS a loophole, albeit a small one. It does not matter if you have a camper in the bed or your truck or not. They only care about what the title says.
This explains why some Sprinter and other camper van drivers had their application for a TIP denied. Their vehicles were listed as passenger vehicles on the title. This also explains why some people are having no problem driving an F-350 and towing a trailer. Their states don't list the GVWR. I did specifically ask if a truck pulling a trailer was treated the same as any other truck and it is.
If you know any RV park owners in Mexico, or have any contacts with Tourism, pease bring this plight to their attention. This could put a serious dampener on their business.