What is the difference in data between the DVD and CD based systems? I have an M3 with a MKIII and was contemplating upgrading to a MKIV, however for the amount of times I use sat nav I really can't justify the price especially when the MKIII is still being provided with the latest CDs.

I have Version 10, so I am due for an upgrade, but being based in Tasmania $300+ is not that cheap considering the place isn't that well mapped. If anyone want to sell V13 or even 14 () on CD let me know.

When did BMW Australia make the change from MKIII to MKIV in their cars?

Thanks