I have a Ram 3500 Crew cab and. like you, wasn't able to see the hitch. My view was actually being blocked by the center head rest on the rear seat so I took it out and now have a good enough view of the hitch to line it up with the pin box.
There are those that install a back up camera and mount the camera in the lid of their bed box or in the cargo/stop light at the top of the cab.
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