I use 14 gauge, 3 conductor extension cords to keep things tidy.
1/2 inch hole drilled in the front clamshell, and another drilled inside the clamshell thru the roof to feed said extension cord
into the cabin.

...the same for the pair in the back.... 16 gauge extension cord, thru the clamshell and into the cabin.

Roof holes are sealed with silicon, just in case. Being inside the roof rail clamshells, chances of water entry are minimal anyway.
Wiring touted to auxillary fuse panel at the knee panel.

Only two 6 gauge wires (red for 12 volts, green for ground) from the auxillary panel routed through the firewall to the
engine compartment (battery). Used existing grommeted pass throughs for these wires.
Yeah..... it's probably overkill..... but I only ever have to do it once.
AND, having everything fused with easy accesss to said fuses help with maintenance and troubleshooting
should the need arise.