2018 Boondock Pre-Wired?

First, are you referring to a TaB320 Outback (BoonDock) or the 400?  Solar was an option in 2018 for both, but neither came prewired as a standard feature.  Also, nüCamp didn’t build the TaB 400 Boondock until 2019 year model.  We changed out the axle on our TaB400 to get the Outback/Boondock axle, wheels and tires on our 2018. Our TaB (built in Jan2018) did have the factory Solar panels and optional external solar connector (SAE/Zamp) installed, but this was an option ordered at the time it was built.

Roof mounted solar is nice, but has limited use, depending on where you camp.  Adding the external SAE/Zamp type solar connector to a TaB is the easiest way to add solar using portable solar panels, instead of roof mounted) and gives you more options putting the camper in the shade, and solar panels in the sun.  Portable panels also extend your peak solar charging times, as they can be moved to follow the sun.
 Cheers 

That is probably because, the DMV went by the trailer’s build date, and not the model year.  The 400s started production in spring of 2017, not sure of exact month, but it was June 2017 before inventory units were delivered to dealers, from what I have read.
 Cheers 

No worries.  While solar wiring was not standard in 2018 model TaB400s, a lot of trailers were however, were built with the option added (ours was).  Either way, adding the connector to,the side of the tub and a solar controller is a easy mod to do on a 320 TaB, and a little more involved on the 400, since the battery is in the back of the trailer.
 Cheers 

Thanks Sharon for clarification of the stating build date for the 2018 year models.  I Edited my post to clarify this.  While production year models at the factory may have started in April, it was June 2017 however, before inventory deliveries of the TaB400 became generally available to most dealers (info from Princess RV in Texas, one of nüCamp’s largest dealers).  There may have been a few preorders delivered before this.  
 Cheers