After a couple minutes of trying to straight up bluff the cops, Dean could tell they weren't going to go away on their own. And he really didn't have time to stand around and argue with them. He was just about to get frustrated and knock their heads together when he heard glass breaking inside. Okay, definitely no time for this.

He grabbed both cops by the collars so far neither of them even thought to reach for their guns. He threw all his will into his glamour, ordering them both to drive away and forget they ever came here. With as hard as he was working it, it occurred to him that he might be leaving permanent blank spots in their memories, but he didn't care. As soon as they wandered back to the car and started to drive away, he shot back into the store.