Stashing cash in spare tires, engine transmissions and truckloads of baby diapers, couriers for Mexican drug cartels are moving tens of billions of dollars in profits south across the border each year, a river of dirty money that has overwhelmed U.S. and Mexican customs agents.

Officials said stemming the flow of this cash is essential if Mexico and the United States hope to disrupt powerful transnational criminal organizations that are using their wealth to corrupt, terrorize and kill.

washingtonpost.com