Is there anyone here who has PERSONAL experience with installing and using this setup? According to emails I have received from PAC, the AUX-BOX does NOT work with the Prius. However in the thread on things that "definitely" work with the Prius there is anecdotal info (I heard of a guy who knew someone who said this works type) that it does. Of course, all the links they provide are outdated.
Looks like the answer is to use the GROM Audio product instead. http://priuschat.com/forums/audio-electronics/51699-diy-aux-in-base-prii-under-100-a.html#post775169