2006 t0 2004 HU swap
 

I was wondering if it possible to put a 2006 bose HU in a 2004 with bose

yes, but it requires swapping the whole waterfall. I did it in my 04.

Did the wiring switch ok?
The 06 has controls on the steering wheel.
Was the color match ok also on the waterfall?

Steering controls won't matter as you don't have them, as for color match...You are replacing everything so there's nothing to match. Only wiring work to do is the hazard switch.

I am considering swapping a newer Bose for the one in my 05 roadster. Id like to have the audio steering wheel controls too which also means a steering wheel swap. What exactly is needed for the swap. Also, what is a "waterfall" (Im a brand new Z owner). Im guessing its the wire harness.

Anyone anyone?