I'm a semi-regular of this Sonic because I'm a Beatrice local. The best the best and fastest way to get served here is to go inside and stand directly at the counter until they acknowledge you, and then continue to stand there until they come up to the front to take your order. I've had bad luck in the past with them not acknowledging me after pressing the button at the park-in stalls, as well as taking an obnoxiously long time to take orders over the drive-thru intercom. While this is a sonic with good food, the service is overall terrible and I wouldn't recommend if you are an impatient person, or if you are in a rush.
I ordered ahead, and parked in the stall and waited for about 5 minutes, and eventually went into the lobby because it was very hot in my car, and I have no AC. While I was only waiting for 5 minutes, I had arrived after the pickup time planned for my food that I had ordered an hour ahead. I came in and waited for about 2 minutes before somebody came up to me and gave me my food, which I could see was ready and sitting on a shelf, not in a warmer, behind the counter.
If a customer orders ahead, and shows up after the assigned pick up time, their food should be brought out almost immediately once checking in. There's no reason for it to not be brought out almost immediately; unless, of course, their systems are broken, and it is then a corporate problem. Overall, I wouldn't recommend this Sonic to be anybody's main Sonic that they go to. If you have another choice, go to that one instead of the Beatrice one. Most other Sonic's are 10 times faster and have staff that look a lot cleaner than this one.