I have bought 2 car flood lights as the reversing light on the MH doesn’t give enough light when reversing. Over the years I have this problem when reversing into spots. I intend to have them on a separate fused switch from the dashboard. My question is: Am I better to run a single core wire and use the chassis as earth or run a double core wire from my feed. I hope to fit them behind a chassis outrider where they are protected from dirt and stones etc