When I was doing the drop down dvd systems in Toyota vans we used fm mods for the audio. Some of them were ghetto as hell regular wireless fm mods, and some of them were the wired ones. The wired ones were WAY better, it was night and day difference, atleast in the kits that we used
it’s a wired FM mod, but made to only work on Sirius units. Every sirius tuner has an FM mod built right into it. 2 Years ago, after Howard Stern left FM, the FCC made Sirius lower the power output of their wireless FM modualtor. The reason being was that you could drive around NYC on a low band station and now hear Howard Stern, completely unedited. There were never any complaints until he switched over.