Motorhome builder Dynamax Corp. debuted the widebody Grand Sport Ultra minimotorhome at the recent Louisville Show, upgraded by adding amenities and six inches to the height and three inches to the width of its traditional Grand Sport GT Class C. With 7-foot interior ceilings, the Grand Sport Ultra features three 40- to 45-foot, four-slide models on Freightliner’s Columbia chassis with either 37,600- or 54,000-pound (tag axle) GVWRs powered by a 450-hp Mercedes MBE 4000 diesel engine. “We went from stem to stern and upgraded everything,” said Rick Horn, vice president of sales and marketing. The upgrade includes LED exterior lights, an electrical system with larger batteries, granite countertops, solid-wood cabinets, nickel accessories, stone tile floors, ultraleather furniture, Amana appliances, deluxe padded walls and ceilings, built-in awnings and larger storage compartments with power locks. MSRP: $426,000