You should be able to figure that one out- DC, takes 2 wires, 1 switch, and a pump. Remember- DC voltage goes one way in a wire. AC goes both ways.
Cut a hole in the rear deck big enough for the size cooler, ahem, live well you want to install and just let it set on top of the gas tank. Use a bungee cord to hold it in place. Knock out the rear window and you can get a cold "fish" while you're going down the road.