Hi Bloddwin
Which cables? The DC from leisure to Van batteries runs under the raised floor until it gets to the front seats. I added a 50A circuit breaker in the circuit in the Boot, to allow maintenance if required.
Most other cables are within the chassis structure and behind wooden panels.
Hope this helps. Callidus supplied all the wiring diagrams with their kit, and although it seems expensive, it was a dream to install. I cannot fault their customer support either.