I just spent 15 minutes sitting in the X5 trying to load a single CD into the hard drive. Got 3 songs played. Don't know if they got stored. What a waste of time! Mercedes fast uploads CDs to the hard drive. You can do a complete CD in about 5 minutes. BMW engineers need to talk to the competition. My wife keeps razzing me about buying the X5 instead of the ML. But, at least the X5 Navi works better than the M-B's.
I'll try the various MP3 players another day.
As a previous post said, it may be best to load the CDs onto a thumb drive or an MP3 player.