The days of a worn-out, aging Navigator are gone. Lincoln has finally given its full-size luxury SUV a proper makeover, complete with a high-horsepower EcoBoost V-6, an upscale appearance and perhaps the classiest interior ever seen in the American SUV segment. Of course, the new Navigator is based on Ford’s all-new Expedition. Both share a new high-strength steel frame, aluminum construction for the body, and Ford’s new 10-speed automatic transmission. Cadillac has held the luxury SUV torch for years with its well-regarded Escalade, but Lincoln could soon be taking the lead.