When we purchased our trailer in 2017 Oliver was just changing solar equipment brands. They changed from Blue Sky equipment to Zamp equipment. I didn’t know much about solar power at the time so defaulted to not getting solar. ScubaRx schooled me about the Blue Sky vs. Zamp architecture and I choose to add Blue Sky solar. The trailer (at least at that time) was “pre wired for solar.” The roof did not include the combiner box but the #6 cable was in place and a battery temperature sensor was in place as well. ScubaRx and I had to run the 4-0 welding cable as needed and other #6 cables in the basement as needed along with the main switch and circuit breakers, shunt, etc. I had the Oliver folks mount the panels and do the interconnections. Technically, the total system was not completely wired, just the hard to access cable was in place. The trailers are not turn key wired by any means, you will have to do the majority of the wiring yourself along with all of the system component installation.