We have an Autotrail. Somehow the bench beds move out as I am driving, especially if we have weighty items on the seats which we do occasionally. The beds won't easily push back as the slats seem to move around as well. It means we have to take everything off the bench, remove the foam seat and back, fiddle with the slats, one by one, as we gradually push the base unit back. We have the same fiddle with the slats on a morning, putting the beds back, all the seats have to come off. Any solutions or ideas please?