If you read my Turbo Timer install, I mentioned that I will hook up the speedometer cable to get a kmh readout on the Turbo Timer.
Here it is:



The GA pin is the "geschwindigkeits abhaengige lautstaerken regelung" or in English the speedo cable from the radio that you will tap into. Its a blue/white cable.

Cut the cable and splice the pink speedo cable from the turbo timer into it and you are done. BTW, the radio should be removed to do that. =)

In order to get the correct speedo to display on the Turbo Timer, you need to program it .

Hit P and S at the same time while in speedo mode.. the display should be Red and SET and 40kmh will be displayed. get the car up to 40kmh and hit the T button twice until the display stops flashing and 40mkh is displayed... thats it you are done.
Good luck.