Mkii Three hole panel??

Is that your tarton observation platform in the background james
it does look like a very comfy chair.
No idea what the panel is for. Sorry.

Does the rear wiring for the rear clip run down that member? I know on 1015 there is what looks like an Anderson connector to allow the rear clip to be disconnected, mounted somewhere in this area? Maybe its to controll the excess wire loop when the rear clip is lifted up. You would not want the wire on the exhaust side of the boxes as heat may damage it.
Hey could be. The main rear harness runs down that side then terminates on the right at the right hand tail lights and/or lights near that side clamp