I didn't mean that knackered bumpstops on their own would cause the rear to drop. I meant a combination of the two would cause the back end to sit lower
especially if there is a load in the back because the springs would be more compressed (which would also likely be buggered if the bumpstops and top mounts are that worn) and so the bump stops would then come into play.
I agree with all your points, especially your point about knackered springs. The only thing I don't agree with is that the springs are most likely to be knackered because of siezed calipers, though I do agree that it can and does happen that way. Lets agree to disagree on that one

The way I see it most owners would notice their rear calipers had siezed almost straight away and fix it, it isn't something you can miss really. Plus it affects all MK2s, including those with rear drums which are much less likely to sieze on.
In almost all cases where the rear springs are buggered the top mounts and bumpstops will be too, and make the problem worse. Some people/garages might not replace the other components and just fix the obvious spring/damper combo, which still leakes you with a knackered top mount.
I would say the top mount and bump stop will wear out much faster than the springs though, since they are only rubber and foam. But that is just my oppinion really

The important thing to say after all this is that the shocks, springs top mounts and bump stops should ALL be replaced when sorting the suspension, as they all will lead to a saggy rear end
