Its a bit strange that the kit is advertised as mk3 / mk4 cabrio - the mk3 uses the same strut setup as a
mk2 ibiza i.e. 2 bolts between the strut and the hub carrier as opposed to one on the "proper" mk4 chassised cars.
Do you have any pictures of the dampers in question?
I'm also sure the mk4 cabrio was more a rebodied mk3 than a proper mk4 chassis.