Sounds like good choices for both on placement, since they are both add on items I wouldn't be too concerned about correctness, I'm sure different dealers would have installed in different places. As far as power for spot a resistor like on heater may work or you could change out to a 12 volt bulb if base is the same. Fuses are always a great idea on any add on item. Hate to burn down a project if ya know what I mean.