At the Peugeot dealer I bought a new aerial, part number:

6561.97

[compare.jpg new.jpg part.jpg standard.jpg]

This aerial is quite a bit shorter then the standard version. Replacing it is VERY easy. Just screws the standard one off:

[compare.jpg new.jpg part.jpg standard.jpg]

Compare the old and the new one, and you clearly see the difference.

[compare.jpg new.jpg part.jpg standard.jpg]

And screw on the new one:

[compare.jpg new.jpg part.jpg standard.jpg]

Looks a lot better and reception is still ok.