I don't know, but that's a ton of money for disks that are 3 years out of date. You could buy a very decent smartphone outright with better sat nav for the same price!
I don't have sat nav in mine, so I'm going on my previous experience with another car (VW Group) that had a Blaupunkt unit.
It might be best to have a look at the original disk and see if there's a brand name (other than Fiat) on it, e.g. Navteq, Blaupunkt etc. I would hope that there's a bang up to date disk available, which isn't sold specifically as being for a Croma.
If you stick the original in a PC then there might be some clues, e.g. text files, version codes etc. You could speak to the maker to find out what the latest equivalent of what you have is.
And you can forget dodgy downloads, pirate copies etc (not wishing to imply that you would). Usually the reader checks for the presence of data that no PC writer drive is physically capable of writing. So you can't buy a new one, take a "backup", then sell the original on ebay!
