My understanding is that wireless is not really wireless, you have to run the wired transmitter from the back
to under the dash where they recommend mounting it.
I just changed out my stereo to a Boss unit that has a backup camera function.
My Z did not have the Bose unit and the sound was so bad I usually didn't have radio on.
The new Boss unit is much improved without changing speakers and I now use the radio.
If you have the upgraded Bose unit in your car just replace the head with a new one c/w backup cam.
I found Crutchfield to be a wealth of knowledge, made the transition very easy.