For those who either want to upgrade their quad headlight wiring to a relay-powered system that also turns on all 4 headlights or for someone looking to do the conversion and wants to upgrade the wiring at the same time, here is a diagram I made with some before & after results:
You can also use this for any other similar application such as offroad lights
Pix:
Factory low beams
Relay-powered low beams
Factory high beams
Relay-powered high beams