As far as I know, my 2007 ATC Bobcat was not wired for solar. For the wiring behind the front lift panel I used super flexible #10 gauge silicone wire - which has many more strands than what the RV industry uses.
On a side note: I noticed that the black wire for the ceiling lights was cracked and exposed in the same spot that your solar panel wire is located - but on the driver's side of the camper.
I noticed similar today on the wires that power the ceiling. The insulation was nicked on both but no bare wires.