Instead of requiring the driver to use such an unintuitive method of enabling/disabling this system, I recommend simply adding a clear yes/no preference to the Driver Assistance Warnings menu that asks the driver to choose whether or not the LDW/FCW/BSW system should turn on automatically with the engine, or whether the driver prefers to control the system manually with the 'Warning Systems Switch'. If the driver selects YES, then those systems he/she has selected to be ON will automatically turn on when the engine is started.
2) Since different drivers probably prefer different levels of sensitivity for Blind Spot Warning, I suggest adding an Adjust BSW Sensitivity nav button so drivers can customize the frequency of beeps from 'aggressive' (which is how the system seems to function now) to 'only if necessary' (such as when a car is directly in the driver's blind spot and the driver begins to move into that space).
3) I want to thank Infiniti for listening to its customers and giving us – in the 2012 model year – the ability to turn off individual warning systems! It's great to see customer suggestions implemented so quickly. Now, perhaps, we can convince Infiniti to change the LDW alert to a "rumble strip" vibration in the steering wheel (like BMW) instead of that constant quadruple beeping!
4) As an aside, my opinion is that the placement of the 'Warning Systems Switch' is unergonomic and unsafe. It's difficult to find by feel alone (especially in an FX), and difficult to see if the steering wheel is in an obstructing position, meaning one must take his/her eyes off the road to both find and press that button. I recommend moving this in the 2013 M to somewhere on the steering wheel, just like the 'Dynamic Driver Assistance Switch' already is.
5) One final note: I suggest that Infiniti include voice commands for the first three separate warning system settings on this screen, plus voice commands to toggle the 'Warning Systems Switch' ("Forward Collision Warning On," "Forward Collision Warning Off," "Lane Departure Warning On," "Lane Departure Warning Off," "Blind Spot Warning On," "Blind Spot Warning Off," "Driver Assistance Warnings On," "Driver Assistance Warnings Off"), all accessible while in 'Alternate Command Mode'. This would give the driver complete verbal control over this safety system, obviating the need for him/her to find a button, navigate a series of menus, or look away from the road.