As for Xantia. I first went online around 1999 at which time I was driving a 1995 Citroen Xantia. Haven't made it to Australia yet but I did notice that French cars aren't sold in the States, is that the same for you?
The 56 was given to me by the PC (I think) as an option when it told me the name Xantia wasn't available but Xantia56 was. Sadly I am a lot nearer to 56 than I'd like to be, but still have 10 years till I get to that milestone!