Change Audio Unit to Pioneer from JBL model

There is no separate audio unit. There may be some third-party head units, though.
See Aftermarket head unit for model 2 2016 Prius | PriusChat

That discussion may apply to your higher trim model too.

Also, in the first sentence they mention a 2016 Prius.

 

Will that suit a 2012 model Prius, pp?

 

Probably not, but they posted in the Gen 4 forum.
I have learned that the Profile information can be deceiving since many have multiple Prius family vehicles.
Earlier today I responded to somebody in the Gen 4 forum. His profile lists 2013 but he was referring to the Prime owner's manual, without specifying what vehicle.
A few just do not update either.

 

Yes, I saw that. I think î would have asked first, though.

 

They stated 2016 Prius in the first post didn't they?
Or am I dreaming?

 

No, your not the one dreaming. I hate this growing old thing!