None, the factory head unit doesn't have a remote turn on lead. You'll have to find a fuse or something similar that only supplies power when the car is on.
This is turning out to be a hassle, because I originally tried tapping into what was the antenna power on lead on the radio harness, and in doing so my car wouldn't start. I bring it to the dealer and they said I tapped into a Class II data cable and that was a bad thing ($400 repair.) I asked the guy at the dealer if he knew anything about where to get the turn on signal from, and he said he knew. So he tapped into a wire in the trunk, going into (or out of) the monsoon amp. It worked great as a turn-on signal, but it took away my XM radio, apparently another Class II data cable. I'm just frustrated because I have all the power and signal cables run and working, but of course the smallest wire is giving me the most hassle.
Sorry for the story, but I'm just wondering if anyone knows a safe place to get the turn on signal that won't screw my car up?