Hi Arjan - well I've got wiring for lights running from three points at the moment - giving one light on either side above the head end of the sleeping area, positioned so that the lights are exposed when the bed platform is pushed forwards with the roof closed so usable as interior lights, and when the bed is pulled back for sleeping they are above your head in bed.
There's another one further back from those which is going to be right up high when the roof is lifted but can be a rear light easily reached just inside the back door when the roof is dropped.
The tail end of all the wiring is coming down to the hinge end of the roof and will terminate in the void between the old roof above the drivers seat (where the panels for the foot end of the bed are stored) which is where all the wiring connectors will be. I can run the power feed from the battery side (passenger seat) up into that void fairly easily.
The sleeping area lights will have switches in the bases and may be swivel LED spots. The rearmost light will possibly be on a two-way switch so I can control it easily even when its way up high when the roof is lifted. For general illumination I'm thinking of a length of LED strip running along each side, warm white, which can be switched from both ends. And where the existing vanity light is I'll replace it with a small swivel LED spot set which is good for normal use and with additional soft red bulb for all night illumination for my wee boy or for use when night driving.
The way I've finished the interior where the roof curve is along each side gives me a void that I can run wiring through, and it is just deep enough to accommodate small flush loudspeakers inside also, plus I've made it just deep enough to hold 40mm plastic plumbing pipe which I'm going to make a cooker vent with on one side at the rear (using a small computer cooling fan). It's now covered with thin ply that is easily removed as needed.
I've got to fit the cooker, but it will be installed above the fridge (which I'm locating on the left, just inside the back door, on lockable HD slides so it can pull out 400mm for access). The slides are available in all sorts of lengths and weight capacities from the folks who supplied my gas struts. Fitting the fridge is the crucial part of the interior because its length will determine where the lock/fold seat my wee lad uses will be pushed forwards to, I think I need another 2 inches of clearance from where I currently have it located. Once that's sorted all the rest of the stuff will be built around those dimensions, and wiring routes can be established behind panels. Fridge came a couple of days ago, and the small stainless sink will be here in a few days. It will be fed via a simple Flipper hand pump, cold only, so low tech and easily maintained.