I need to power a device or two while my car is off (no key in ignition).

The power requirements of one device is 150mA, 12 volt DC. And the other is an Android smartphone. I don't plan on having the power running all the time, so I guess I'm not too worried of killing the battery.

What are my options? I was told that I have 2 options:
1) Fuse box
2) Battery

Are there other power sources? Which do you suggest I use?

I really don't want to burrow a new tunnel from the cabin/interior to the battery. Does anybody know there is a pre-existing grommet/hole, and whether I could fit in the wiring needed for my project?

Here are pics of under the dashboard of my Civic: Powering devices without the key in ignition - Album on Imgur