go buy three spools of three different colors of wire (white black and red?) Also get two replacement bulbs for your tailights (two filaments)and two generic bulb sockets. Glue the new bulb sockets into the tailight assy.'s and run wire from both new 'tailights' to the front of your Jeep. Put a 7-pin connector in your Jeep grill and wire up the lights. Then build a jumper wiring harness that attaches to your tow bar and connects your Jeeps together.
I did this on my CJ so I could flat tow it also. This is exactly the same concept as the magnetic light but it is clean and built in! Good luck.
1977 CJ-7, D44 corp 20 detroits, D300, NP435, 304, 4" BDS, shackle reversal, 33X12.5 BFG MT's