Yep, the 40002 - Neo iOn SP is what we purchased and installed. Unfortunately, I have no idea whether it is the same as the SoundLinQ. All I know is that I talked to an old friend of mine who is a high-end stereo installation instructor and he recommended.
Best Buy charged about $55 for installation. Then it's lifetime guarantee for the install. Thus, I was able to bring back and have them change the install from the MD Change emulation mode to the CD Changer emulation mode - no extra charge.
As best I can tell, there is capability for 12 playlists with an as-yet unlimited number of songs per playlist. We have more than 99 songs on one playlist and it continued playing past song 99, although the track number went a little funky. As far as I can tell, here is how the stereo/CD changer equates:
CD Disc = Playlist
CD Track = Song Name
Thus text shows the Playlist name as the Disc and does not show the Artist Name. Still pretty cool though.
Also, the model we bought includes a second input for Auxiliary in the event we subsequently want to add some other source. We'll probably never use it, but the reason I bring it up is because pressing the CD button on the stereo toggles back and forth as follows:
First touch = CD Changer
Second touch = CD Auxiliary (currently unused by us)
Third touch = Back to CD Changer
Fourth touch = CD1 Changer (IPod)
Hope this helps.
Edit -- I happened to notice on the installation manual that this is indeed the SoundLinQ model. Don't know the significance of that, but looks like you were correct.
Also, to further answer your question, random seems to work - at least rudimentally - however, it does seem to repeat songs a little too often. That may also be because we don't have a whole lot of songs on her IPod yet. Hopefully it will be a more true "random" once we have a larger sample of songs from which it can choose.
Also, haven't really tested it too much yet, but I believe you have full access to control directly from the IPod if you want to select a specific song by a specific artist without slogging through an entire playlist by hitting the track forward button until you hit the right song.