I'm curious to see if taillights are also negative switched.
one would need to run a hot wire to the back and than a hot wire after the bulb al the way back into the switch in order to go though a switch and into ground.
positive switching would save approx 50% of the cables here. Just a switched cable to the back. However this wire is now only usable for the taillights. still powering 1 item in the rear would cost ~1 carlength on positive switching and ~2 car lengths on negative.
powering 6 items it would be 6 for positive and 7 for negative (1 thick hot wire to the back and then thinner lines back to all switches for each item).
After rewiring (and shorting) a series III LandRover I prefer to do positive switching just in order to have as little hot wire as possible around the car in order to avoid shorts on damaged cables.
If I'd make additions I'd likely either do positive switching at the dash OR do hot switching using a relay close to the item to be switched. Don't forget to use a fused signal wire as well
, I might just run a 2.5A permanent 12+ and a 2.5A iginition 12+ wires behind the dash to tap in to with switches. Runnig 1 8-core cable to the back would then give me the option of steering 8 relays. Alternatively one might install a 4 relay with remote:
http://www.banggood.com/12V-4CH-Channel ... 60987.htmlrunning 1 hot wire to the back and such a unit would allow me to switch 4 items. Would be great to enable work lights on a remote when the car is parked in a dark corner