Anyone install solar on their DRV?

[MTK46]

I'm installing two of these panels on the roof of my DRV.
https://www.ebay.com/itm/1-200-Watt-...53.m2749.l2649

Here in the controller I bought.
https://www.ebay.com/itm/Renogy-Rove...e=STRK%3AMEBID

My question is the pre solar wiring installed from the factory seem too small.
Has anyone ran new wiring down into the bay? How hard was it to fish down?
I'm going to mount my controller on the wall between the propane tanks & the underbay storage. My extra two batteries will go there also.