My new R Class has the command system with a single CD, and I can see a plastic cover over the slot where the Navigation disk goes. Can someone tell me if I can purchase just the navigation drive and any suggestions for a source? Thanks.

 

Yes, you need the navigation drive and GPS splitter.Both parts are available from your local dealer for somewhere in the $400-$500 range. You remove the radio from the dash and and the navi drive mounts to the radio with 4 screws. Then you need to pull up the driver seat and carpet and install the GPS splitter (which breaks off the gps antenna to the navi module).