Radio Controller Replacement?
 

I'm looking at replacing the radio with an aftermarket radio and speakers, thus making the already broken controller above the Heat/AC controller even more useless then it was before.

I have this idea that perhaps I could remove the controller and replace with a Fitted GPS, has anyone done this or something similar?
I'm curious about transitioning the power supply from the traditional female adapter it will come with to something that runs off the radio supply.
Is this possible without creating an electrical hazard? If so where would be a good starting point resource wise?
Has anyone done anything Similar?

Not knowing what make/model/year vehicule, here is some of what I have experienced with the vehicules I owned/own
1- Most radio manufacturers offer plug and play for newer vehicules...this would be a radio made to fit with some kind of connector that plugs into your existing radio harness and to the new radio/nav system.
2- On a Saturn Vue 2003, I installed an aftermarket radio (no nav system) KEEPING the original harness and just splicing into the wires near the original harness plug. The headache I had doing this was figuring out which wire was doing what (power, speaker +, speaker -, etc etc) because the time, I had no wiring diagram and there was no info on the original radio (even though, normaley all radios have a wiring diagram sticker on the unit). Then just stripped the sheath and soldered new wire to it. I happened to have multiple colored wire so I kept the same color code. IF you do not have different colored, mark them using masking tape. You need to be sure it is taped/shrink tubed properly.
Hope this helps