Shares of RV-maker Winnebago Industries, Inc. (NYSE: WGO) rocketed higher today after announcing an acquisition of towable RV manufacturer Grand Design for $500 million in cash and newly issued shares. The market roared with approval for the deal, and the stock climbed through the morning, getting a boost from an analyst upgrade from Robert W. Baird. Shares were up as much as 29.8% during the session, and finished 23.7% higher.