it looks like a fairly straightforward piece of wiring, just feeding the 3.5mm jack into the L+R audio feeds on the cd changer.
this wont charge your ipod and you will have to change tracks from the ipod itself.
you want a simple cable to do a simple job, this is it.
obviously you will need twin RCA to single 3.5mm cable too
i would be tempted to get one of these, but i have just UPGRADED to a rns-e Mk2 and now have no need for anything else. but that costs more than £12!