regarding the button and exiting the car;

a- push the button and hold it a bit longer and it shuts everything down w/o having to push twice (I got into the habit of this and now its second nature)

b- if you only push the button once lightly, the radio stays on....BUT it shuts off after time or when you lock the doors....nice if you still want to hear the stereo while you are exiting and gathering your stuff.

Also make sure you use the "other" IDrive shortcuts...hold the center idrive knob in one direction for several seconds and it behaves differently.

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2013 X5 35i M Sport