Incredibly slow service. It took us 10 minutes from start to finish to get 2 slushies and 1 Coke in the drive-thru at 3:30 p.m. on a Friday ... and there was NO ONE in front of us.
Unfortunately, slow service is the norm here and we only ever order drinks. My kids always laugh about the Sonic poster that says something to the effect of "We wait on you, not the other way around," because it's so clearly the opposite at this particular Sonic location.
Just a note: the service at the Sonic in Sun Prairie is so much better.