Confused.

To remove a windshield mount you flip the little lever and put it out of sight so nobody steals it.

To use it on another vehicle, you flip the little lever, remove it, put it in the other vehicle, and flip the lever back to stick it to the window.

I'm not saying the $30 bean bag is better or worse then the $7.50 suction cup windshield mounts, but they are by no means a permanant mount, they are meant to be removed and reattached all day long.