It seems to be hit and miss whether they are fitted or not for some unknown reason. In the early days of MINI2 it was said they stopped fitting them because it was considered a security risk. Someone can come along smash your window, pull up the seat, pull the ring and have full access to the valuables you hid out of sight in the boot.
I have had the displeasure of having to unhook the rear seat by squeezing my arm between the seats and reaching round. I wouldn't recommend it
