There is a wiring adapter to convert a late antenna with inline connector, to the older square connector. When I installed a new Hirschmann in my 92 500E, it included the adapter. The old antenna was toast anyway, and a brand new one for ~$175 was worth it at the time. Photos are
here... note this style antenna is NOT for the 94-up models. As you can see, the new antenna does NOT include new grommets/seals, those must be purchased separately if the old ones are fossilized.