After a week of trying everything and searching the web, the 2005 Sprinter VSS wire / cable is located in the Radio Harness. The cable is called "Speed Sense" by Mercedes and is the BLUE/RED/WHITE wire. Just connect the Pink Nav wire to this Speed Sense wire all works fine. I found it made installation easier by removing the top Air Vent directly above the radio. This helps you when you need to tuck the wires out of the way when sliding the radio back in place.

For the record ,I did find 2 Speed Sensor wires ( N2 & N3) under the drivers seat. These are apparantly for the front and rear wheels and don't give a correct reading for the Nav system. I also looked at the harness under the car connected to transimission and it has 8 wires. According to a friend at MB, he says these are IN/OUT speed wires which monitor each wheel. None of these will work.

After all the work, it was in the easist place. My guess is that the German/Euro shipping Sprinter offers a Nav Radio system like most newer US cars. Of coarse the US Dodge version does not.