The Monster RadioPlay 300 links my vintage mp3 player to my vintage car stereo adequately.The controls, though manageable, are not quite intuitive. The link is not always crystal clear as I would have hoped due to radio/atmospheric interference, but all in all it's a good little unit. The only difficulty is when your chosen FM frequency is interfered with and you need to select a new one while trying to drive.A simpler user interface would make that less problematic.