Guys, check this site out!

[Sankekur]

Well as much as you guys dislike, that might be the OEM position for the aerial....

 

[Fordkoppie]

The rear one might be for the phone, but the radio antenna is in the rear screen.
That "unicorn" is some fool's idea of a cheap/easiy fix or just really bad taste

 

[Sith]

You right, the radio antenna is in the rear screen, but wasn't that from '90/'91 onwards? I remember having a '89 525i with the electric antenna. If memory serves me correct, the M5 was available in Europe from '88 onwards, so it is possible that early cars had some form of aerial/antenna before it was incorporated into the rear screen. Must say, it looks original.

Oh damn, just had a look at their ad, and it's a '93, so it could possibly be some idiot with a unicorn fetish!