Sonic – Small Ice Cream Slushies for just 79¢ Each The links in the post below may be affiliate links. Read the full disclosure Here. March 21, 2017 by SMFM Leave a Comment March 22nd, be sure and stop by your local Sonic restaurant to score Small Ice Cream Slushies for just 79¢ each! No coupon is needed – just mention this offer when ordering! The new Ice Cream Slushies come in the following flavors: Grape, Blue Coconut, Orange, Cherry, Blue Raspberry and Strawberry! YUM!