From reading the article, it may not be a "new" law, but adherence to the old law.
This may very well put an end to the "paper only import":
"The Mexican Federal Government recently put on a push to stop illegal imports of American used cars into Mexico. This new effort has taken several forms:
~ As of Sept. 1, 2014, SAT has issued new rules for permanently importing used cars from the United States. The biggest change is that the individual importing the used NAFTA car into Mexico must first prove that the car has been formally EXPORTED from the USA following US CBP laws...."
Source document for the complete article: http://yucalandia.co...rs-into-mexico/
proper attribution: YucaLandia/Surviving Yucatan. © Steven M. Fry