THE Chrysler Group will use its ‘‘home’’ motor show at Detroit in January to lift the covers on a pair of diverse concept models.The company has released sketches of the Chrysler Nassau and Jeep Trailhawk concepts which will feature prominently on the stand at the North American International Auto Show.The Chrysler Nassau concept is a four-door, fourpassenger luxury coupe with an emphasis on driving dynamics. The exterior design carries the theme of the large metal expanses on the 300C through to the next level, and leans toward an exploration of what could be a future sedan in the brand’s line-up. The Jeep Trailhawk concept brings together the iconic aspects of the Jeep range in a single model.It merges the core features of the Jeep Wrangler with the more sophisticated Grand Cherokee to produce a car that sits right across the brand values. Derived from the all-new 2007 Wrangler architecture, the Jeep Trailhawk concept taps into ‘‘Jeep Rugged’’ attributes to provide classic proportions, unsurpassed off-road capability and a new approach to open-air freedom. The headlamps, cropped and peering out from beneath a diagonal brow, produce the countenance of a bird of prey, and the inspiration for the Trailhawk name.