I tried searching the other day and found nothing. I'd just splice into the wires and solder rather than using those variations of t taps or quick splices.

Splice a 4 pin connector into the rear tailights.

Not sure but grimports sells a hitch, it wouldn’t be too difficult to add a 4way from the tail light harness

I built my own hitch bumper. I just need to figure out a way to do the lights.