Gabriel was at a bit of a loss. He hadn't actually expected the hunter to trust him enough to step in the car, to be honest. All he wanted was to mess around a little, but now he had a neigh-unconscious Winchester in his car and no idea what to do with him. Deciding it would be fun to watch him rack his brains over this, he eventually settled for putting him to sleep, healing his injuries and leaving him in the car next to the highway. He snapped himself invisible and waited around to see what would happen.