The Financial Post reports in its Friday, Jan. 20, edition that Donald Trump's Twitter-fuelled bid to crimp free trade in the auto industry began with a warning to Detroit's Big Three about building factories south of the border. A Bloomberg dispatch to the Post reports that later, Mr. Trump fired off threats to German automakers -- specifically BMW, which is far along in completing a plant in San Luis Potosi, Mexico, that is set to churn out 150,000 cars a year. However, as the Republican president-elect takes office Friday -- and potentially makes good on a promised 35-per-cent tariff on vehicle imports -- some sizable auto industry targets for his Internet ire remain. The heart of the U.S. auto industry may be in Detroit, but much of its muscle lies just across the river in Windsor, Ont. That is where almost 6,000 Fiat-Chrysler workers bolt together the Chrysler Pacifica minivan and Ram pickups. All told, Ontario assembly plants have about 27,000 autoworkers, including 5,600 people assembling Chevrolet SUVs and the sporty Camaro at two General Motors plants. There is also about 7,000 folks at two Toyota installations, stamping out Lexus RX crossovers, Corolla sedans and RAV4 trucks.