you need newer CD changer - the changers have their firmware too but not user upgradeable... if you are looking for MP3 player, and consider buying a newer CD changer the CP600 could be a good alternative - you will lose the CD ability but pick up MP3 with SD cards... about the same cost to buy a changer vs the SD player...

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E53 X5 4.6iS
147K mi - Sold May 2013
Tireprints left in:
USA, Nicaragua, Costa Rica, Panama, Russia

E53 X5 4.8iS built 2005-10-17
66200 mi - June 2012
96000 mi - June 2013
112000 mi - June 2014
OEM fire extinguisher
OE first aid kit
OE tow hitch
OE TV module
OE aspheric mirror
K&N air filter
black/white badges
rear camera
4-channel video recorder

Here is the list of things I have done to the X