We took our first 5th into Mexico a few years ago - registered to husband - didn't return the permit - and then sold it in Canada. We now have a different 5th, and are returning to Mexico in January ...
BillB; There is a thread on the boat subject. They are not owned by snowbirds. They are "cruisers" and sailors. Some have homes in Mexico. Some live on the boats for years at a time. Most did not lack the permit. Moisheh