iDrive ver. 2.0 has
3 function buttons, and
4 shortcut buttons.
And
1 5-way knob / controller.
Function buttons:
Menu - brings you back to the main menu
Back - brings you one step back
Option - opens an additional option sub-menu if available (like mouse right button)
The shortcut buttons: CD, RADIO, TEL, NAV are really just shortcut buttons - to access some menus directly. Yet you can access them via main menu if that suits you better.
