I think you will find that you are definitely wrong..It is true
The CM5905 uses a hardwired security tag system See
http://codedradio.info/?i=bn&st=cm5905
JUMPERS = SOLDERED TAGS = HARD-WIRED
Others in the BMW Alpine Model CM59xx series are also all HARD-WIRED SOLDER TAG versions.
http://codedradio.info/?i=bn&st=CM59
I CAN VIRTUALLY GUARANTEE THAT YOU WILL NOT BE ABLE TO OBTAIN A WORKING CODE FOR FREE FROM ANYWHERE ON THE INTERNET BY JUST QUOTING THE SERIAL NUMBER
You may have a slight chance by visiting your local BMW Dealer with your car documents but these units are that old then I don't think they are listed anymore on the BMW database....and if available the code is unlikely to be given out for free.
Judging by the number of questions for these CM59xx codes on the Decoding Forums then the only successful way of getting your radio working again is by opening up the casing and maybe using a soldering iron.