Quick question on original radio/stereo from my 1990 Jetta TD.  Sorry folks about the non-vanagon content but i really don't know what to do at this point.  On this particular version of radio i have managed to use up the 4 tries one gets to input the stereo code before the radio locks up for good.  Don't even ask how i managed this, as i speak my head is hanging in shame.  I have heard that i need to have a new "chip" installed to unlock it.  Is there another way?  Does anyone know if this security "chip" can be bypassed?  I don't need this security for the stereo but i would like to keep my car as original as possible.  Any suggestions?
Thanks in advance.
87  Vanagon  GL  7pass
90  Jetta  TD