If its an E53, Grom Audio offers a kit. I have it in My E39 and its easy to install (replaces CD changer). Works the bomb. You can play music from your phone/mp3 player and use for phone calls too.
If its an E53, Grom Audio offers a kit. I have it in My E39 and its easy to install (replaces CD changer). Works the bomb. You can play music from your phone/mp3 player and use for phone calls too.