I designed my own halo ring for my beloved hyundai tiburon. i wanted to transform it into a transformers eye. and i succeed after many calculations :D , still don't fit perfectely but it comed out very nice.
for the HALO RING use support, and choose your infill (i think i made them with 80%, but you can try with less to make them more transparent)
for the HALO RINGS SUPPORT 1-12 don't use support, and use infill 20% ,to make them more transparency
the supports are all different , each one have another size so that's why i numbered them, and they are oriented on the halo as in the picture i provided.
using a catepillar , some paper sheets , a cardboard , pen, cutter and other tools , and an actuall headlights part i started to make measurements and design the halo and after the halo supports wich was very hard to design.