The Becker Map Pilot (Option Code 001 + Pre-Wire Code 508) is now available for the 2013 C-Class, GLK-Class and SLK-Class. I have used it a few times and find it to be much more intuitive than the Nav+4 or UMI that we used before. The Pre-Wire option is $200 and the Becker Map Pilot itself is $600 and can simply be plugged into the dock. The biggest flaw with the kit was the lack of a detailed instruction manual. Here it is!
Thanks to Nash for finding it for me!