I like where this is going. I have thought about the same thing...specifically swapping the positions of the radio and HVAC controls. But since all my radios are single din it hasn't gone any further than considering the possibilities. I have also thought about the possibilities of moving the HVAC controls to the area where the cigar lighter is (obviously I would have to extend wires and get a custom cable)...this would give even more room for a larger computer screen.
Couple questions:
1. Can I assume you also plan to fab a bracket to hold the radio? I wouldn't trust the "pressed fit" solution long term...especially with the way I drive my cars.
2. Have you verified that the temperature slider still functions freely with it sitting on the bottom like that? Going out of memory, the back of the HVAC controls are quite open and it would be easy to cause binding in the control unit itself.
3. I see in your last pic that the cable for the temp slider is now very visible....will that tuck back up under the dash?