Think about this: If you do these tricks the new menus can not be erased after the procedure. But it's not dangerous or harmful for your phone
To enable the headset-function, you have to short-circuit the "3" and "4". After a short time there is "Headset" on the display Now, menu 3-6 is now enabled!
To enable the carkit-function you have to short-circuit the "4" and "5". After a short time, "Car" is shown on the display and the menu 3-7 is enabled!!