There are several ways that vehicles are imported in to Mexico
1 Big auto makers, example Mercedes-Benz, Porsche, and some of the big three from Detroit.
2 Mexican Government and States.
3 Industrial entity's that require special vehicles.
4 Zonas fronterizas, Tijuana, Mexicali, Ciudad Juarez, Reynosa, etc.
5 Non Mexican Citizens that are travelling in non RV vehicles.
6 Recreational Vehicles, A class, B class, C class, 5th wheel trailers and pull trailers, the vehicles used to pull the last to do not have the 10 year permit, oonlythe 180 days as the Visa de Turista.
I will venture to state that the ban is on the vehicles that have the license plates from the border that are not supposed to go down to the interior of Mexico with out an importation permit as a tourist, unless the importation of all private individual vehicles are prohibited.
There have been a lot of vehicles smuggled in to Mexico, the vehicles come from the U.S.A. some are stolen some are not, vehicles in Mexico are expensive.
navegator
