I put one in my 38' DP a few years back, and am about to put one in my C. For the DP, I over-engineered it, took a piece of 3/4" plywood, cut to reach the studs, and about a foot tall. I painted it white, so it wouldn't stick out like a sore thumb, and mounted it with self-tapping screws along the studs and wood screws in between. I then used a pair of short lag bolts to hold the mount to the new mounting surface I created on the wall. In the front of the coach, I cut a piece of 3/4" plywood and stained it to be similar to the wooden housing for the 12V CRT television. I mounted a small inverter inside the housing, and ran a 2x6 across the housing to be right behind the plywood at the mount height. This was held in at the ends by 6 screws, and then the stained plywood was screwed in all around the perimeter and through the 2x6 as well. Once again, lag bolts into the mount, plywood, and 2x6. This one held a 42" TV.
Both were full-motion mounts as well. I stowed them for travel by pushing them in as far as I could and I used long pieces of velcro that were screwed into the wall behind the TV to wrap over and under, velcroing to each other in front of the screen. This kept them against the walls and prevented them from tilting down on bumps as well. I ran that setup for a couple years (and thousands of miles of full-timing) before selling the coach.
The plan for the install next week is to mount it to a cabinet side. Once again, I'll use a 2x6 on the back side of the cabinet wall (inside the cabinet) to spread out the load, and lag bolts through the wood to secure it. I'm going to try out a different approach to the velcro this time, by putting two small pieces on the top corners of the TV, and screwing the larger pieces to the wall behind it. this would probably be a bit more aesthetically pleasing than a long "strap" of velcro around the TV when not in use.