The 2018 Buick Regal GS trades the traditional sedan shape for a Sportback liftback body and adds a twin-clutch rear differential more commonly found on sports coupes. A 310-horsepower V6, Brembo brakes, and a HiPer Strut front suspension round out a genuine engineering commitment rather than a badge-only performance package. Read on to see why Buick is chasing a very different kind of buyer with this one.