To the best of my knowledge this wire is used in European cars for a 
park light or something.  I may be wrong but thats what I've been lead 
to belive every time I install an ignition switch that wire has been cut 
off at the base.  I haven't found any problems in doing this and have 
installed quite a few switches in my time.
   
  Kyle Wade
  Keeper of the Volks-Motorsports page
  Home Page - http://www.scruznet.com/~vwmaster