In the market of buying a 2014 Evo X and wondering what the differences in the factory radios that come in the Rockford Fosgate packages are. Appearance wise one has just the power/volume knob and the other has button for most everything.

Is the one with the buttons for everything the nav unit? Can the one with only the power/volume knob have nav installed on it?

And is it possible install an aftermarket deck and keep use of the factory system? Going from threads I have read it doesn't seem so or work is required to do so making it seem that keep the audio stock is more logical.

Thanks