I guess I'll keep my outside spare now , after thinking it over. (Thanks for trade offer though, Jim) There's really no good answer; inside takes up space, outside is inconvenient to open tailgate. Pick up truck under-bed spares are really a pain.
Juan, that's a good idea for a locking mechanism. My carrier is pretty tight, so it dosen't move unless I'm parked on a tilt. I can see how it would hurt if it started swinging while you were loading something.