On a less adventurous note:

Jim,
I've been snooping the I/K bus on my
'00 528i. Is there any docs on the address
used by the CD changer? I'd like to avoid
borrowing a unit to determine its address, and
how the radio/tape (on my car) unit discovers
the CD changer (and when) as well as how the
CD changer is given permission to write to the
MID etc. I've already worked out the checksumming
and the overall frame structure. I'd like to
understand as much as I can.

Thanks,

Tom

I think you will not find that info anywhere outside of BMW hands. Even if someone sniffed it out and published it I think it changes frequently.

Playing with the digital message codes is not something I would want to try.

While I do not agree with BMW keeping control of setting software options, I do support their keeping control of the communication language - otherwise we could bugger up the operations very easily.

The only hope for interchangeable communications & audio stuff is if they will work with others to creat an open standard interface - but that is unlikely to go too far for marketing reasons.

Cheers
Jim Cash