pop off your fuse box panel, locate on the map the SINGLE blade connection (not a fuse location - 2 blade) labeld "ACC" this is a Ignition switched Accessory 12v source. just get a flat blade crimp on connector from radio shack or anyplace that has that small part. crimp to wire and stick it in there. I have my hidden power socket hooked up there. useful for devices i want to turn on and off with ignition... Radar Detector... No power, no beep. Cop no hear/see, less chance of ticket!
There is enough space to run the wire up around the edge of the fusebox behind the panel, just need to take off the drivers side knee panel. then bend the back of the crimp connector down a bit.
Also that connection is not affected by RAP (Retained Accessory Power)