I know that ****** sells seperate power cords that can be led directly to 12v. I once wanted to do this as well, but thoughts against it. I don't think that you can just simply cut off the cigarette lighter thing and run it to power, because then you still need a ground. Not sure how the wires are on the inside of that thing.
If your Dad is smart on electrical, perhaps he can look into it.
If your Dad is smart on electrical, perhaps he can look into it.