Mexican automotive exports climbed for a sixth straight month, rising 15% on a year earlier due to a 51% surge in light truck shipments. That in turn reflected the growth in sales of such vehicles in the U.S. General Motors led the way with a 67% jump (30,800 vehicles) due to production of its Silverado pickup to meet that U.S. demand. Yet, its U.S. exposure may count against it given the likelihood of supply chain disruptions from the ongoing NAFTA negotiations. GM’s room for maneuver is also limited by its recommitment to South Korea. The least exposed Mexican automakers to the U.S. ar...