Mine came pre-wired for a roof mounted satellite from the factory. There is a label on the roof where the wires are located with instruction for where and how to drill an access hole.
I have a VuQube portable satellite dish. Many of my camping friends have roof mounted dishes and cannot get a signal at the COE parks we frequent. I carry my VuQube out, look for an opening in the trees, and BAM! I am watching TV in no time. I have never been in a campground where I could not get a signal with my VuQube. Winegard makes a similar product as well.
IMO the portables are a better way to go, not the old tripod dish, but the self tracking, or remote aim portables. The tripod versions are a pain and take two people to get set-up. The portables are easy one-person set-up, and only take a couple of minutes. They are the same unit as the roof mounts, just not permanently mounted.
2011 Ram Truck 2500, Crew Cab, 6.7L CTD, 4X4, 3.73 Rear