For cars equiped with CCC (car's before LCI) you have this :
http://cgi.ebay.de/BMW-TV-Freischalt...ht_2126wt_1167
For cars equiped with CIC (idrive with harddisk) you have this :
http://cgi.ebay.de/BMW-DVD-TV-Freisc...#ht_814wt_1167
This is just the idea of type of part. I don't know the sellers so take care to their notation ! Anyway, I bought one (i don't remember to who) but it worked fine for me !