I think that's the only place they can go. And yesterday, unbeknownst to me, one of them came loose and was sliding around in the little storage well. I thought my car had developed some type of new rattle! I had one of the middle seats folded down and thought I caused a new rattle.
I also just realized that the seat belts have extra cloth folded up on them to keep the clip from banging the wall next to the door. Someone got out of the back last evening, and the clip didn't slide down, and I was going crazy with the noise. Wish I had known about that little trick sooner!