I hope that works for you. I've watched several of those videos but were for water tanks.
Found this nifty little dual USB charge item to go in the cigarette lighter hole. Has a + 12v and - spade on the back no power adapters needed. drilled out my lighter whole 1/8" with unibit. May put one in the glove box also.
https://www.dropbox.com/s/p64fecb5dncamrs/2014-02-22%2014.04.16.jpg
https://www.dropbox.com/s/eqiqs7p64xbgyrz/2014-02-25%2017.59.08.jpg