There's been an 'Omega' in the Holden range for a few years now, usually a retrimmed Commodore. 
That's absolutely right - Holden have used the 'Omega' name on a few Commodore models over the years.
I was lucky enough to drive the previous model Commodore around eastern Oz for a long time for many, many happy miles on all sorts of roads (based on the Omega B with a few mods & improved safety, but bigger engines) - smashing car & very comfy & reliable.

They are marketed as large family cars down there rather than executives, hence the different interior styling to the European Omega - I prefer them, but that's just me.
Back on 2006 when I had my Commodore, it was the best selling car in Oz..... says a lot of good things about the Omega-B design.

The latest ones are homegrown Australian.

I'd have another at the drop of a hat (if I had the $$$$)
