I just moved mine this past weekend, but haven't driven it yet. I pulled out the instrument cluster and ran the cable under and through the back of the dash to the MB sitting behind the glove box. You really can't see the cable at all.

The latest firmware 4468 on the MB is a big improvement over the previous one 4360. I had all kinds of volume / static issues. I still can't get the same, large font used by the rest of the Nav unit.