If anyone out there is like me , to where there was no trace of the wires for the sensor than maybe I can save you all the hours I spent figuring out how to run new wiring so here it is ... This info is for the 2005 E55 AMG , might work for other models but not sure. So I had to figure out where the M4 connector was to run 2 wires back down to where the ambient temperature sensor was supposed to be, I had a friend who works for mercedes send me the wiring diagram including the wire colors ( see first pic) so i had to find the M4 connector which is located under the front sam unit on the left bottom i circled it i the pictures and cut the #3( gray and brown) & #4 wires(Gray & Yellow) and solder 2 new wires and run it back down to the driver side foglight where the ambient sensor location is in the mesh grille.Since my sensor + harness in my car were gone then I had to also find somewhere to buy them and connect them the wires i was about to run down from the sam. I couldn't find the harness for my car new but if you look on ebay you will find people who sell the sensor used and at times they plug and wires are still connected to it, so that's what i did , bought the sensor with connector and a few inches of the wires attatch to it, just enough to solder back on to my new wiring. the front sam is easy to remove, in fact you don't have to remove the whole thing just unplug 3 or 4 connectors on top that are in the way then unscrew two torx in front of sam( second pic i marked with a red marker where screws are) and unclip it from the back (same pic where i drew the arrow),Then slowly and carefully pull it out a couple of inches so that will give you just enough room to unclip connector M4 from the SAM then cut the #3 gray and yellow wire and #4 gray and brown wire and either solder or use connectors or whichever you preffer ,new wires.