Aero is/was a Saab sport trim level... common as mud.
Limited is a Dodge/Chrysler trim level.
Exclusive started as a Base+1 model Vectra C trim level, and was carried onto the Insignia as the same poverty spec with alloys.
Might as call it Merit or Unicorn

Buick would be a contender, but with the new Insignia, this is already a rebadged Buick, so that won't work either

All in all a complete waste of internet space even discussing it.
Incidentally this is the meaning of Insignia...
insignia /ɪnˈsɪɡnɪə/
noun noun: insignia; plural noun: insignia; plural noun: insignias a distinguishing badge or emblem of military rank, office, or membership of an organization. "a khaki uniform with colonel's insignia on the collar" synonyms: badge, crest, emblem, symbol, sign, device, mark, seal, colours; More decoration, medal, medallion, pin, ribbon, star, award; military slang fruit salad; informal gong "his tunic bore the insignia of the Légion d'Honneur" a sign or token of something. "the ruins are devoid of moss and ivy, the romantic insignia of age and decay"
GM are so stuck for names that they resorted to calling their primary european model "Badge"
