A reader supplied spy shots of a five-door Regal variant testing with a more conventional four-door sedan iteration. In Europe, the 2017 Opel Insignia and 2017 Vauxhall Insignia are very likely to switch wholly to five-door trimmings. But, North America is tipped to receive regular sedan styling.
If we had to venture a guess, General Motors could simply be testing the five-door variant at home for use abroad. But, there’s also a Regal TourX trademark sitting around for Buick to utilize, too. That could be a wagon, or it could be a more useful liftback body style to bring some extra “white space” to the Buick brand.