The 944 spoiler was a drag-reduction device first, and a rear-end-lift-reducer.
If you can find a photo of an original 924 in a wind tunnel (doing the "smoke test") compared to a 944 with the little rubber tail you'll see quite a difference.
968 body was changed sufficiently enough (especially at the back end) that perhaps the new "wing" was justified for reasons other than purely looks...
