I have an ice>Link Plus iPod adapter. Used it in my 2000 E39 M5 for about 9 months, then in my wife's E46 300i for a couple of months.
Gives you instant access to the first five playlists on your iPod and will display song text info on the display. Not as good for searching as the later DICE units or the Intravee, but if you want fast access to 5 playlists, it works great. Works fine, we just don't need it any more.
Comes with the extra long cable (10 or 12 feet, I think) that will allow the unit to be mounted up in the front console of behind the glove box and still connect to the CD changer connector in the trunk.
Works with iBus BMWs that have the analog 6-pin audio connector for the CD changer. Sorry, I don't have a DSP adapter.
$50 including shipping. PM me if interested.