There is an OS update, the final version is 4/100 which is displayed in the top corner as 4-1/00. The final FW version was found on V32 OS is from around 2003-4 adds the 3D perspective view, which is a novelty but doesn't zoom out enough.
To view this menu google 'BMW MK4 hidden menu' or similar.
The maps you want are BMW Professional, but you must be careful not to buy the maps for the idrive nav, which was shipping in some BMWs in 2007. You want DVD maps compatible with cars as far back as cars around 1999. In fact the maps for the iBus Pro and Bus navs are the same discs, only the coding of the nav drive changes it from color to monochrome. Again, don't buy the business or professional maps for iDrive.
The OS CD is about 9$ to buy, the DVD maps are about $250 I think.
For the OS, there are some people who are modifying the OS, adding in POI, custom splash screens and custom color schemes.
http://neiloakley.com
In summary, your nav is based on the VDO dayton system first launched in about 1990 so don't expect it to come anywhere close to a modern smartphone, or new BMW in looks, features, performance or cost to own/operate.
Also the motorized screen breaks sometimes and costs $850 so if it starts to act up find a way to fix it in the upright position.