i didnt think they were very important on an escort i once had, i was wrong. i nearly destroyed my arches over a nasty bump with people in the back.
on my bravo they are held in with a single plastic clip for each part, one for the top and one for the bottom. crap design really, the clips are brittle and easily damaged when a clumsy fool like me is trying to pull the old spring off. i repaired the clips with a bit of tape, if you can find all 4 parts of the clip. if not get to a scrapyard, i dont think fiat will sell the clips seperately and new bump stops wont be only a few pence. then again how much can a lump of rubber cost, well at fiat quite a lot i would guess?