I think i have the same problem... My English is to bad.
When i start the car for a drive my sounds goes away after 1-2 min. No radio sound, no cd sound and no gps sound. But sometimes after 10-30 min when i press the on switch it work again until i stopp the car. When i shall drive again it´s the same problem.


Edit: I have a x5 2001 3.0.