I use a 120 watt folding portable that works very well. I did upgrade the controller, but left it attached to the panels back. It came with 2 connecting wires, 1 with clamps and 1 with the same connectors as the other end. I bought & mounted a short 10 ga wire with the same connector to the battery. I cut it in half to wire the end to the battery & trimetric shunt.
https://www.amazon.com/gp/product/B0057ZQJ12?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00
In my class B my battery box is under the side entrance and visible from under the side. I drilled a small hole in the side and have the connector hanging out there. A quick and easy set up.
I like being able to park in the shade and move the panel out in the sun and adjust it during the day for max solar gathering. I would not want to mount panels on the roof. It worked well for 13 days in FL in Feb.