So the other day i was in a hurry to a meeting, pressed the button to shut off the engine, but left the window down. Went back and press button two twice so i can roll up the window. Guess what? I forgot to press the button again to turn to OFF. Long story short, my battery got drained.

Question is, is there a way to set the G to sense that key is not around, and then it will automatically shut off everything?

I would like to know too. When I first got her, I left it in aux or on mode until my neighbor told me.

Nope. On a positive note, the system allows you to leave your car on with the doors locked in case you have to run back into the house for something.