i started to play around with a double din tv headunit out of an import evo, with the intention of building it in like this
i just got very annoyed trying to make up suitable support for such a heavy unit, as its kind of just empty space behind the heater controls. plus where the dash drops down slightly above, it was just too close to the top of the unit, n i figured its either gonna melt the dash or overheat the unit lol
if u have the patience to brace the unit somehow, in a position where it isnt gonna melt stuff or overheat itself, then it shud just simply be a case of making up a nice fascia surround to fill the void around the unit