I did a similar install with my Newmar
I added a shelf inside the existing opening for storage"
then added a nice thick plywood door with heavy duty hinges, to which I attached the mounting bracket for the TV.
Here's the finished product.
I don't travel with the TV there though, it only takes a couple of seconds to lift the TV from the bracket, I then stow the TV in the bedroom. Works for me. I could probably drive with the TV there, the set up is certainly strong enough, but I know me, if it can go wrong, it will. LOL
Kaye