Looking at Hindin's excellent post, I have a couple of questions.
I believe that the broken piece puts tension on the divider rod to hold it against the switch. This keeps the switch closed so the car knows the divider is in place.
My first question is; As a temporary fix, could a rubber band or small bungee cord be wrapped around the rod and the bracket to keep it in place?
My second question is; Would it be possible to put the divider in place, then mark where the rod lines up with the switch and mark it. Then measure the distance between the divider rod and the switch and glue or tape a slightly larger piece of plastic or wood on it to activate the switch. Like the expression "A bump on a log"?
Just a couple of thoughts.