For current pickup, I use the usual technique of ø 0.15 mm wires wound on the axles, soldered on a small piece of self-adhesive copper. Be careful not to overflow the bearing area of the chassis. Flexible wires are soldered onto the copper areas.
These flexible wires run through the holes in the chassis corresponding to the return spring hooks.
At the front (compartment side), there is no discreet passage for the red wire. Indeed, if I make it go forward to pass through the toilet, it can interfere with the drawbar movement. So I stick a copper tape along the chassis to make the connection at the other end.
Hover over the picture to see the details.
The wires go through the interior fittings by an existing blind hole in the kitchen, which I just had to open.
The strip uses the quadruple voltage technique, hence the need of two electrolytic capacitors.
The strip supports are made of three layers of 1 mm thick polystyrene, to form jumpers that can be mounted on certain partitions.
Intermediate support (orange arrow):
Note the headrests made of polystyrene half-tube.
Kitchen side support: