In reference to your PM....
I connected the positive wire to 12v constant in the wheel well but you can connect it to the large wire in the bottom of the fuse box under the hood. I tapped into a 12v switched (powered with the key on) wire under the steering column. There is a connecter under the column that has 4 wires. the 12v switched wire is green with an orange stripe i believe. I connected this wire to the relay like the diagram below. it converts the 12v switched to a switched ground with the key on. I have been drinking a little tonight so i hope this makes sense (redbull vodkas!!!)