dumb newbie question about rear torsion

[chunkstyle]

hi guys --

can anyone please explain to me why, on old beetles, the outer ends of the rear torsion springs extend out through the bushing retainer end caps on the torsion housing 4 or 6 inches? is it because a shorter torsion spring would be too stiff?

when you look at such a setup, is the thing that you see protruding through actually a long, internally-splined tube on the spring plate with the torsion spring inside it?

i've always wondered -- why the long extension?

i've seen end caps without through-holes for sale various places. are those for buses or something?

sorry if this is a really dumb question.

thanks!