Yes, this is a bit outside the screen problem, but it is pertinent to car UI. Buttons/Joysticks give a form of tactile feedback, they don't give positional feedback. Take a button. Pushing it does give tactile feedback (she feels that she pushed the button), but it's quite possible that the button wasn't pushed enough or long enough to register the push, same with joystick up/down. Flipping a switch for example is different. The position changes, and latches. She is certain that her intentions (turn on the light) were either carried out or not, because the switch with either be in position one or two. Buttons/joysticks require a second evaluation, to check that the button knows it was pushed. It's a subtle difference, but serious. Sliding the gearshift all the way forward, we just know it's done. Likewise pulling up on the handle, hearing the ratchet sound, I know that my parking brake is on.