61 13 ... Antenna elbow plug on radio receiver
WARNING: This page is about a different car, the 2002 BMW Z3 and 2001 BMW Z3. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
This repair solution is only possible up to model year 10/ 2000. Replace entire antenna cable on affected vehicles. Refer to 65 21 020 REMOVING AND INSTALLING/REPLACING REAR ANTENNA (Z3 ROADSTER)
.