Keyed Power Source
i've used the radio for a source before if you really want something in the cabin.
here is where i put the switch for my fan switch....out of the way but easily accessible. although i don't use my cig lighter, and the 2ndary power port works for any other needs.
oops..forgot the pic
If you look in there, it will show you where you can get retained accessory, key-on, and always hot 12V power from the fuse panel just inside the driver's door. All you need is a wire and a standard male spade connector.
For your application, you'll want either the retained accessory (key-on, but stays on after you shut the car off until you open the door) or the switched (key-on only) 12V power source.



