This antenna fits securely on the unit and is suitable for retrofitting, provided the screen does not have too much coating, otherwise use the built-in antenna with a splitter, again only if this antenna does not have a built-in amplifier.

A normal DAB+ car antenna fits and a conventional car antenna for FM reception, you have to clarify which antenna plug is used by the antenna installed in the existing car radio and possibly get an adapter.My device only runs on DAB, because I am still missing the adapter.

I have ordered this antenna to go with it.
Pioneer DAB+ Windscreen Antenna