Perhaps the most unique show promotion being offered during consumer days this week at the Pennsylvania RV & Camping Association's annual Hershey Show at the Giant Center in Hershey, Pa., - officially billed as "America's Largest RV Show" - is a special warranty on any diesel pusher motorhome manufactured by Iowa-based Winnebago Industries Inc. "We're offering anybody who purchases a Winnebago diesel motorhome at the Hershey Show a three-year, 100,000-mile factory Winnebago all-inclusive warranty," reports Scott Degnan, vice president of sales and product management for Winnebago. "It's our normal warranty extended to three years."