Hi
This may be of interest to other owners - most models - most years.
I have been able to obtain 2013 Australian maps from sieras5
Road Map Australia/New Premium Zealand cic 2012) - read thread - for my E46 2004 318 with Professional Nav. Download and extacted using 7zip and burnt to Sony DVD-R using Imgburn at slowest - 639 Meg. Going by others experiences with sieras5 I do not expect any issues. Maps loaded on SatNav ok. Yet to drive around to see if any more detail in country Victoria.
Have read of v19.1 available but only seen reference to Aus-High and have not seen any 19.1 Aus-Professional.
Cheers