Buick's Riviera concept coupe seen at the '08 Chicago show, was the first new Riviera to appear in Chicago since 1999. Painted “Shell Blue,” the tightly stretched carbon fiber body features a trihedral waterfall grille, gull-wing doors, Formula One styled side mirrors and top-mounted chrome portholes. The prototype Riviera sits on 21-inch, 10-spoke forged aluminum wheels with low-profile tires, and the powertrain is engineered to accommodate a hybrid propulsion system. Upholster in Royal blue Alcantara suede-like covering and sandy white leather, the 2+2 place cockpit is accented in subtle icy green ambient interior lighting.