The 1990-1993 kit is for the round pop up lights, the 99+ kits are for the fixed headlights.
The SCCA Rules state that all glass headlights must be taped to avoid shattering on the track in case of contact. Why mess with tape when you can keep the factory look or better yet get that exotic race car look by applying colored film from Lamin-X? 5x Racing uses Lamin-X film on our race cars and we love it! It works too, it saved us from having to buy new tail-lights after the 5xR Spec Miata had contact with a tire wall. We just peeled the old film off and reapplied new Lamin-X film, there was not even a scratch on the lenses.