if its not connected to anything than jus take it out. probly just a left over wire from the previous owner

 

i have the cable too. it's a pink square cable right? im not sure wut it does but if u take it to like a local car audio shop and ask them they'll tell u

 

Its a printer port used to print out data for the ECM i believe. Its not on all cars, just models germany was using to gather information on. Mine also has the port in by B5 S4. Im not completely sure of that though, all i know is that it isn't used here in the states for anything.