Digital radio
WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
Digital radio means that a much higher number of stations can be picked up. In addition to the audio data, other information is also broadcast. The sound quality is close to that of a CD or MD.