In the wiring loom under the tool tray there exists wiring for interior lights which I have used to fit an LED to the rear bulkhead. This simply works on / off with the door switches and seems to be Independant of the BCU
This is confirmed in the Roadster wiring diagram I posted above Tim. As previously said I doubt the +4 is any different in this area.
Thanks for this Tim, my LED’s arrived today. Current plan is to have a try over the weekend, which hopefully will be successful 🤔. I was also thinking of putting a light behind the seats so great to hear that the wires exist below the tool tray.
Good luck with the hookup Kenny, let us know the result.