I was looking at a new Dodge 3500 the other day that someone had installed a large amber light bar on top of. A lot of 14ga stranded THHN run through the engine compartment, near the turbo down pipe, under the truck to the bed. In the bed there was a 8x8 PVC box where it spliced on to the cable from the light bar. Adhesive ty-wrap mounts up the back of the cab and across the roof. The amount of work put into doing it wrong was really impressive, in a nauseating sort of way.
I'm 99% numb to this stuff after so many years. I've learned not to comment, just blink slowly, grit my teeth, and walk away. Don't touch it, or you suddenly own it for eternity.
Glad it wasn't one of our trucks...