The 2013 3500HD LTZ trim level is only offered on extended and crew cab body styles and augments the LT's features list by adding foglights, a locking rear differential, a heavy-duty trailer package (with integrated trailer brake controller), dual-zone automatic climate control, steering-wheel-mounted cruise and audio controls, remote starting, heated, leather-upholstered front bucket seats with power adjustments, a floor-mounted front center console, Bluetooth and an upgraded Bose sound system with a USB port/iPod interface.