Mexican auto exports jumped 10% on a year earlier in February after a 1% drop in January. That was the fastest growth rate since August and was led by a 29% rise in truck shipments. The increase may mean U.S. truck sales will rise for another month in March. Ford’s exports dropped more than 50% after scaling back production of its Fusion model. Meanwhile Fiat-Chrysler’s shipments jumped 29% on higher truck shipments after the launch of production of the Dodge Journey crossover. Future developments depend largely on U.S. trade policies. Forthcoming changes to environmental regulations may...