Dash power outlet

I've been wondering the same thing because I power my radar detector off of the dash outlet and I have to remember to turn it off every time I get out of the car.

i would think all you have to do is tap into the ignition and wire up the Power outlet to the hot wire that is only on when the key is in...

Like steedastang66 said, the power outlet needs to be connected to a wire that is only hot when the ignition is on, as opposed to a 24/7 hot wire. I did this on an old SUV. My power outlet was broken, so I added a two-outlet adapter under the dash.

You have to open the dash and probe a wire to see if and when it is hot. I've never done this on the Mustang so I don't know the specifics. But as an example, the headlights would be something that are 24/7 hot, meaning they can be turned on, even with the ignition off.

I would say that the radio is not 24/7, but after you take the key out of the ignition, it still has power for a few minutes, or until the door is opened. But if the power cuts off once the door is opened, that should work. Like I said, be sure to probe the wire. Try it with the key in the ignition, then with it out but the door closed. And finally, open the door and see if the power remains. If the power turns off, you have your wire.

Power point

The best way would be to do as I did on a 2000 Mustang. I installed a 12 volt relay in the power wire to the power socket and used a wire that went hot when the key was on as a signal. It worked great, but with the way the dash is built on my '06, it would be hard to get to the wiring to do this.