SONIC Drive-In(R) has the perfect way to help kick off summer with a sweet treat that won't impact your wallet. On Wednesday, June 3, SONIC will thank its customers with Free Float Night, giving away free 10 oz. Root Beer Floats from 8 p.m. until midnight at participating Sonic Drive-Ins. SONIC plans to give away more than 3.5 million Root Beer Floats to customers coast to coast during this special event.