Business Insider – Mexican authorities have discovered what they believe to be a narco-tank factory run by drug-trafficking organizations in Nuevo Laredo. Narco tanks are cars and trucks that have been specially reinforced to withstand ballistic attacks from both high- and low-caliber weapons. These armored vehicles are used to help ferry drug shipments into the US and are used for protection against rival drug traffickers and the police.
http://www.businessinsider.com/mexico-discovered-narco-tank-factory-2015-2