I'm installing 3rd function this weekend using Summit's kit. I have questions about wiring. I've seen there are different options for wiring - e.g. wiring direct to battery, a keyed/ignition or fused power source. Wiring direct to the battery seems the easiest route. What are the pros/cons of each option? Pretend you are explaining this to a middle schooler (that's about my knowledge of wiring).