While I think that, as corrupt as Mexico's government is, there might be a problem with smuggling (both ways) I'm not so sure that, given the right oversight, this export/import area could be a good thing all in all.
In almost any country a customs department of another country is treated as, although it is not, sovereign territory of the country that is receiving the export.
This is nothing new.
I'm just not so sure that I want a representative sample of Mexican corruption and smuggling smack dab in the middle of Kansas City.
Kansas City International Airport is called "International" because it already has an "International" port ~ stuff flies in. Stuff flies out. It is checked going both ways by people authorized to do so.