Just run a white wire from the bundle to the bar. Then any time you need a switched power, just take it from the bar. Install a second bar that gets constant power all the time. Take that lead from the terminal on the main cable where it runs up from the floor to the fuse box. There should be a bare terminal under the black plastic cover. If what you are installing requires a decent amount of current, install it using a relay that gets power from the two bars. In line fuses are also nice to have. You can just ground to the body. You can use the bars to get power for the electric fans, fuel pump, radio, ignition box, electric water pump, etc.