An improved beam shaping means for an external and/or roof antenna has a parasitic beam shaping means configured at a distance below the upper or outer surface of the electrically non-conductive region of the vehicle structure. The parasitic beam shaping means is configured, provided or attached in the material of the electrically non-conductive region of the vehicle structure or at the underside or inside of the electrically non-conductive region of the vehicle structure. The parasitic beam shaping means is arranged and/or configured in such a way that it, viewed from above, protrudes laterally beyond, at least in certain portions. The antenna mounting region or portion and/or an optionally provided counterweight surface and/or is arranged laterally thereto.