I was up at the rescue yesterday. Rocky was sitting on the lap of one of the volunteers when I pulled up. I'm not sure if he knew the sound of my car, or if he could see me through the distant window from the volunteer's lap, but I was sitting inside my car, window rolled down, when I suddenly heard that most distinctive of scream!
He saw me/knew I was there and started screaming shortly after I pulled in. As soon as I entered the room, he calmed down and started talking, singing, etc.
He has been quite well-behaved at the rescue, stepping up for everyone (but me.) I am hopeful that we will find a permanent home for him soon, though he doesn't seem to mind being at the rescue right now. There is certainly a lot of activity for him to watch, and he is kept well-stocked in toys!