I replaced a tube type TV in my 5er. I ended up removing a frame that was around the TV and built a shelf for a new flat screen. I mounted it by drilling 2 holes through the TV's base and bolting it to the shelf. I added a angle across 2 of the mounting holes on the back of the TV and then ran a strap from the angle to the corner. It travels great.
I had about a 3" space between the old bottom and the new shelf. I added a vertical support in the middle and mounted a radio and DVD player on each side. I found a matching piece of paneling and cut holes for radio and DVD faces to fit through. It looks like it was built that way at the factory.
It is very hard to access the back as the TV fills the opening. I took some pics of all the TV connections and stored them on my laptop. I can look at the pics and feel for matching connection when I have to change any hookups. Worst case is removing a couple of bolts.