Parrot MKI9200 Mute Lines

Hi everybody I have a question about the Parrot MKI9200 and the Prius.
I recently bought a Parrot MKI9200 to install in my 2010 Prius. I saw from the Parrot website i needed an Adaptor. I got that adaptor (specific for the Prius (PC000005AA)) and when i got it i noticed that the mute lines from the MKI9200 are going nowhere.





I'm pretty sure i plugged it in correctly since the connectors are a little different from eachother and there's only one way they can match.
I read from the adaptor instructions that not all the cars have a mute line.

My question is, has anyone already done something like this? Is it supposed to be like that? Is it working?
I would like to know before i take apart the dashboard and try it.

 

Just talked to a Parrot expert and, for anyone interested, this was his answer :
Outside of vehicles with separate amplifiers, and a some specific Ford vehicles, the mute wires don't hook to anything. The muting of the radio is simply handled by the bluebox of the MKi9200 in all other cases.