Here is some good info on what the build dates of MP3 support

http://www.bimmerboard.com/forums/posts/243524

It is hard to know exactly when the radios were cut over, but I do know for sure the 961 and 962 BM53 Radio shows ID3 text as I have one of each of those radios. The changers must have been built from 09/05 but they were not avaiable from BMW unit early 2007. Units are built in Hungary and then go to Germany for distribution to dealers and mfg facilities

Martin