Answer is over here...
I have never hooked up anything electrical in my life so bare with me.
When I hook up the connections from the minipc, screen and usbhub (via 3rd output), do I need to use something like 16 gauge wire? Or is that only for the connections going to the car (like the battery, ignition etc)? Basically I am going to hook up the connections from the pc, hub, and screen myself and have a local shop do the car connections. I was planning on just stripping the very end of the power cables of the pc, hub, and screen and wrapping these ends around the ends the wires coming from the p1900. Will this be okay without adding any extra wires between them (it says something about those wires being "pigtails).