Detachable Spring under front seat

Hi I recently took my old beetles seat out to be replcaed by a new set.
Its a while since i took them out and I have discovered a fairly large spring which i believe to have been fitted to the old seats can anyone advice where abouts i would place this spring on my new seats?

Any help is much appreicated
Adam

If the new seats are the same style of the old seats, there should be a hole in the seat frame where the spring hooks up to.

It would help if we knew the year of the Bug, since there have been several different styles over the years.