I used the Roadmaster diodes and wired straight to the lights; underneath the car was easy aside from getting my large carcass under there far enough.
Note that the Tracker stoplights will illuminate when the brake pedal is pressed no matter the key position; I tied to that wire to illuminate a monitor light in the MH so I could tell if the toad brakes were actually working or had gotten hung up.
One other thing; assuming you have a TPMS add sensors for the toad. How would you know if your toad had a flat or hot tires from dragging brakes etc?