There seems to be some errors in many listings for Oldsmobile Ninety-Eight Regency. Some list it as a trim level, some as extra info that is not a trim level, and some as part of the model name. Regency is a trim level and should be listed in itallics on all listings.

Done
What about these:
http://www.imcdb.org/vehicles_make-Oldsmobile_model-Regency.html

Those should all be "Ninety-Eight Regency" with "98" spelled out as a word.