I didn't use the hollow bolt. Bought several flex conduits- hated them all.
So- made my own.

Used the end fittings. Had to cut the male thread shorter where nut fastens. They have an o-ring inside of them. Perfect for a piece of 3/8 polished stainless. They slip in & out of o-ring to adjust the headlights. Why 5-6 wires? Buckets are grounded, one high, one low, one turn, one running light. I run 4 wires.






You could do the same thing w/ the hollow bolt. Get a stainless acorn nut that will thread over the hollow bolt end. Chuck it up & drill a 25/64 hole dead center of acorn & polish. Then bend up stainless for wiring.