There's limit of 4 Slushes per order and you'll need to mention the offer when ordering (which means you should probably call ahead to make sure your local Sonic is taking part).
The promo excludes Real Ice Cream Slushes and cannot be combined with other offers, such as their daily half-price drink Happy Hour. Add-ins are extra.
A medium (20-oz) Slush is normally around $2.
