Fastening backup camera to motorhome

I am new to motorhomes and am trying to install a backup camera on a 2002 Coachmen Leprechaun. I have found internet "how-tos" that say to mount the camera just run a couple of screws into the back wall of the RV to hold the camera mounting bracket. Before I go and do that I would kind of like to know what I am screwing into. From what I have read, I think the wall would consist of a sandwich of foam insulation between an inner layer of some type of thin paneling and an outer layer of fiberglass panel probably backed with a thin layer of plywood (luan). There may be aluminum or wood framing between these layers to provide strength to the wall. If this is the case I would expect that screws for the camera mounting bracket would first pass through fiberglass then thread into the plywood. That should provide adequate support for the camera, I think. If there isn't a layer of plywood behind the fiberglass, then I don't believe the fiberglass panel alone would be able to hold the mounting screws. I hate to drill a pilot hole only to find out the plywood isn't there. So, am I thinking too much about this or can I assume that the plywood (or some other similar layer) is there that will hold the screws and just get my drill and start installing? Is there an easy way to tell if there is plywood behind the fiberglass? Plan B is to mount it on the ladder but I would rather not. I am open to other ways to attach the camera as well such as using an adhesive. Any ideas, recommendations, or advice is appreciated.

Thanks - Mike