When I swapped out a TV in my Challenger what I found was Thor screwed metal bars to the TV, then attached the metal bars and TV to a wood panel which they then screwed to flimsy supports in the wall. I changed all of that out.
The thread where I posted the process is
http://www.thorforums.com/forums/f27...r-tv-3647.html
Could be you have something similar for mounting.