I have the RB1 that I removed from my Durango, and Sirius, the RB1 displays the song title and artist, as well as station info, etc, I can not answer the MP3 question, I have never tried, but I have read on other forums that the MP3's wont play on the RB1, the draw back is that you cannot play a cd and use the nav at the same time, it's either or, I have often wondered why the ordering page does not allow one to order the RB1 with Sirius, perhaps because of the problem that I and others have occasionally, when starting the vehicle there may be a sound distortion that many have called static on the sat stations, turning the vehicle off and restrting clears the problem, my occurences are very rare, but they do happen.
Bob