thread digging:

through my research i have found two companies that allow limited control of the ipod via the stock headunit of the 94+ alpine/becker tape player headunit with the CD changer option:
Monster makes an adapter called the iCruze
http://www.monstercable.com/icruze/
you must also purchase the m-bus link and then connect this adapter to the CD changer port on the head unit. I believe that this (and the dension product) make it impossible to use the CD changer with their products.

Dension
Densionusa makes the IceLink v1.1 that works with the pre 99 apline/becker head units. At this time, I can't find the information about these units on their website.

Both of these allow you to change songs (tracks) and ffwd/rwd with the controls on the head unit.