We chatted with the plant's CEO for a peek behind the curtain. BMW’s electric future is taking shape on the outskirts of the Mexican city of San Luis Potosi, some 450 miles south of the U.S. border.

When BMW does announce the site of the plant – reportedly narrowed down to either Hidalgo or San Luis Potosi – it is tipped to work its way up to 100,000 vehicles per year at the new location ...