I am really impressed with how good it sounds over the FM Modulator. It is crystal clear for me. Leaving it on 88.7FM I don't have to change it anywhere in Kansas I have been so far (which is all of it on I-70 and area's north of I-70 and a good part of Kansas City and its sub's). I will get a Sirius compatible head unit on of these days, but this was a great way to start!