Head unit upgrade

You would have to be a little more descriptive. The 2010 model II and model III non-nav sound systems in the the US are very different. Do your back doors have a small speaker on the upper trim in addition to the lower panel speaker. Also look under the front seats to see if there is an amplifier. These would tell us if you have the base radio or the JBL upgrade, as it is in the US anyway, to better help answer you question.

 

I believe, the US 2012 head units had a minor/major change and are not an exact fit for the prior models. No telling what the European models have.

 

My US 2010 Prius II came with the base radio. Without knowing all the details, this likely is our equivalent of what you have based on description and photos. Do not install any other Toyota Prius factory upgrade radio as they are all junk. The 2012 NAV unit you mentioned (SAT and camera plug-in capable) will not "directly" interface, plus the amp that it requires is junk just like the speakers. Your Electrician could do a modified install with "all the parts" taken from the donor car and the proper wiring diagrams, but the return would be disappointing. To keep it simple I would recommend just upgrading your base system with an after-market NAV-HU and better speakers if that's what you want. SAT, cameras and steering wheel control interface are easily done with the right unit. I went all out with my linked install, and that might not be what you had in mine, but it may give you some ideas and options. Hope that helps.

frodoz Stereo Upgrade | PriusChat