Cereal keeps saying that "I guess there's nothing I can do" when a few valid solutions have been offered.

This is simple - there needs to be more friction between the ball and the socket. This can be achieved in three ways:
1) Make the ball bigger or the socket smaller. A coat of clear nail polish on either or both will accomplish this.
2) Rough up the ball with some sandpaper. This is tricky cuz you don't want too make hte ball smaller at the same time.
3) Make the joint 'stickier'. Dip the ball in something that dries tacky like hair spray or a sugary soft drink and it will gum it up a bit. Might even accompish this with the mirror in the car by dipping your finger in Pepsi or something and dabbing it on the exposed part of the ball and letting it seep in the crevice between the ball and socket.

All of this was covered before.