Our 5er is stored and I'm not sure what the exact clearance is, but looking at pictures of the 5er and TV hooked up, seems to be about 6 inches. As far as hitching up, I have to lay the back rest of the back seat down, sit up high in the seat in order to see the hitch and king pin.
So I am going to resolve the issue this spring as I have in the past with our other 5ers by fabricating an "L" bracket and installing a 6" round convex mirror high on the pin box, then I can line up through the mirrors.
The things we do to enjoy life :S