I like the fact that we can push a button to fold and unfold the mirrors. We have a somewhat narrow two car garage, and like that we can fold the mirrors prior to entering the garage. Same is true exiting the garage, keeping them folded until we are out of the garage. I would not like it if they were to only fold or unfold when locking or unlocking the car. I think some new Volvo's do this. However, I don't see a problem if it is something that can be programmed, just don't lose the push button option. It is a function we look for when looking at new cars.
FYI, I have noticed that the mirrors will automatically unfold when you reach a certain speed (20 mph or so).