I installed it myself in a Toyota Highlander.

The only connections for me are 12v constant, 12v switched and ground. The rest is just routing and hiding wires.

BTW... I didn't try to connect it to the car radio. We did that with another kit in another car. It seemed like everytime the cellphone changed sites, it muted the radio.

Have fun... If you are fairly handy, it isn't too tough.