There is really only one company in the business of supplying Nav Databases for automotive use and that is Navteq.
Almost all of the systems in use including aftermarket units rely on their GIS data.
In the EU you can buy most of their map data directly from them, but in North America you will usually be referred back to the OEM source of the Nav System because of the way the data is licenced for distribution. Because they are the sole source of the GIS data the costs of the data disks are so close between different OEM suppliers that there would be no advantage to hacking a disk from one source to work in another, and the disks have had anti copy encription for about the last two years.
The only reason for hacking one of their disks would be to create a data disk for a system not supported here such as creating a disk to allow the EU only version of a VAG Navi to work with a North American database which was never offered since those units were never intended for sale or use outside of the EU or to try using the larger database supplied with one system on another such as the dual layer 2004 DVD disk that replaced the single layer disk from 2003 that Honda and some others use which do have substantially more POI's and many more mapped areas than the DVD disk supplied for the Benz.
Since both the Honda and North American Benz drive units are supplied by Alpine (EU Benz use Becker)the effort to hack the Honda disk might be a worthy project if the Benz unit is dual layer capable.
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!