Help us put the THUNDER back in Thunderfest! THE BIGGEST CAR SHOW IN SOUTHERN CALIFORNIA! THIS FREE EVENT BRINGS YOU HUNDREDS OF CLASSIC CARS, HOT RODS, BEER & WINE GARDEN, GOURMET FOOD, AND FUN VENDORS. The Covina Downtown Merchants Association (CDMA) and the City of Covina proudly present the Annual Thunderfest Car Show & Music…