Radio reception

Hello guys, again the old topic: I have very bad FM radio reception in the A2. Built-in is a current car radio. I have already read a lot about diversity, different systems in the A2 etc. I am not a specialist, I just want a good radio reception. Therefore my question: can someone please tell me based on the following photos, what condition my A2 provides and what I have to do with it so that my radio (with normal Iso antenna input) can operate reasonably. g FM reception has. Thanks! Pictures 1 and 2 show the rear window. I think this is already a first hint, which system is installed here. It shows, I think, the two antennas. Figure 3 shows the diversity box installed in the trunk (I think J515) Figure 4 shows two cables that arrive at the radio: 1x Fakra and 1x antenna plug. I can take more pictures if I have forgotten something important here. Can someone help me because of the pictures? I just need to get more pictures. passable FM radio reception. How can I reach the (with or without great effort)? Many greetings Ashley Edit: the radio is 1U. I don’t know. which radio was installed here original.