Cool, you could move the scan gage up to the ashtray spot, it fits perfect:
Granted, I didn't make any panel or anything, I just stuck it in there, but it just the right size to blend nicely with your interior. Set the screen color to match your sweet head unit, and away you go
And no, it doesn't look that messy now, that was during my inclinometer install, I cleaned all the wires up and made it a bit cleaner. I do like the idea of a panel to hide the inverter, something like the one you made. Very nice.