Winnebago Industries Inc WGO shares are facing selling pressure Monday after a short selling firm suggested cracks are starting to show at Winnebago.What To Know: Hunterbrook published a report Monday morning claiming Winnebago's best-selling Grand Design RV, which accounts for about 35% of the company’s total revenue, appears to be experiencing “widespread frame failure.”Hunterbrook highlighted multiple customers who have publicly posted about frame failure and suggested that Winnebago is aware of the defe ...