While it's just a rumor, a Regal wagon could genuinely make sense for Buick.
Opel Insignia Country Tourer
Opel brought out its entire Insignia range for the 2013 Frankfurt Motor Show, with particular attention paid to each new models refreshed features. Like its colonial cousin, the Buick Regal, the Insignia has gotten a fairly standard mid-cycle freshening that's designed to tide customers over until the next-generation model arrives.
The last piece in the Opel Insignia family puzzle is this: the Insignia Country Tourer. Whereas the Insignia Sports Tourer is honed for urbanites, the Country Tourer beefs up the wagon for gravel-minded folk with larger tires and higher ground clearance, underbody protection panels and body cladding. A Haldex all-wheel drive and electronically-controlled limited-slip differential can shift torque between the front and rear axles, and between the rear wheels.