Hey, you never know . . . when heavy winds will topple a giant Mega Millions sign onto your auto-body shop.

A highway billboard bearing the New York Lottery’s famous slogan crashed over the side of the Brooklyn-Queens Expressway on Meeker Avenue near Manhattan Avenue in Greenpoint yesterday, narrowly avoiding traffic before smashing into a car-repair shop below.

High winds whipped the region all day, reaching more than 50 mph.