Power Inverter Install - Wiring Always Look Worst Than It Is

This project is to install a new 1500 watt power inverter to replace the old 250W that plugged directly into a 12v lighter outlet. But first, I had to upgrade my 8awg cable to a 4awg (Connected to battery), which ran into a power distribution box (1)-4awg in & (4)-8awg out). I also drilled new holes within the attic area for simpler access.