The Gateway 500 MOST is the premium Dension systems Gateway product allowing full iPod and USB browsing. The device controls on-board equipment built on the MOST bus. Gateway 500 emulates a CD changer and uses CD changer controls to access off-board audio sources including iPod/ iPhone, USB devices and Dension Gateway accessories. Special note for BMW owners: to be able to display and browse through the song titles, it is necessary to have the BMW "MP3 Retrofit" software option programmed by your car dealer. A quick test of your car"s capability to display track titles and browse music is to see whether you can browse through MP3 files on a CD inserted into the car"s single CD slot. If you can, then the BMW MP3 Retrofit is already installed in the car.