I know what you mean. I thought the current placement was odd too and that two attachment spots would have been a good move.
I actually purchased my screen online and paid around $145. When I purchased the car there were 2 Limited's on the lot. Both had the screen in a box in the back with one of the 3rd row seats folded down. Neither had the screen listed on their stickers but I guess I just assumed since they each had one that it came with the car. When my car was delivered it wasn't included. When I inquired I was told that it wasn't included. I said I thought that was an odd way for the factory to deliver accessories to the dealership by putting them inside new cars being delivered. The sales rep didn't have anything to say about that. You'd think after buying a $46k car they could throw in a privacy screen. Oh well live and learn I guess.