iPod adapter to 2011 Prius JBL

I just got this adapter, it is part No WT-IPD1. Supposedly compatible with base 2011 JBL audio system. I'd like to find a picture or diagram of the back of that "radio" (maybe even the actual number) before I go removing stuff, to confirm that this has the correct 12 pin plug which I unferstnd goes into a socket oterwise used for a CD changer. Can anyone help ?

By the way, these adapters had been going for up to $50. Now sold on Amazon for $23.50. Hope I can make it work.

 

UPDATE: The WT-IPDT1 adapter does (hooray!) work for the factory standard 2011 Prius head unit (no nav) - number 86120-47290, although the folder navigation using the head unit is a bit odd, and the steering wheel control has limited functionality. What you do is unplug the existing 12 pin CD changer plug, and plug in the one from the WT adapter. I understand that GROM and others have some sort of splitter cable. Possibly 2011 Prius' wiring harness is capable of supporting a true CD changer. Anyway, $20 or so is pretty good for getting proper iPod capability (NOT just through the aux connector). By the way, the aux connector continues to work as an alternate choice to the built in CD or the new "CD1 - iPod.

For the record, here is a picture of the rear of the head unit.