Easy as pie. I bouth my power ant. from a garage sale, sealed for 43. Then I tapped the constant i nthe hatch, grounded to the side of the body on some bolt that was already there and ran a signal wire to the back of my head unit and spliced it in.
On the back of MOST aftermarket headunit's, the wire is blue. soem newer models have dual 12+ switches. One for an amp (constant with radio and cd/tape on, one for ant, that shuts down the ant when you move to cd or tape). Its really an easy job, took me 30 minutes becasue I took my time running the lines.