Looking at installing a Nexus 7 tablet in place of the head unit in my 06 mustang, looking at basically copying this guys setup.
DB Link NF105 Reference Noise Filter
Clarion EQS746 1/2 DIN Graphic Equalizer with Built-in Crossover
Behringer UCA202 Audio Interface
Micro USB Host OTG Cable with Micro USB Power
USAMS Compact High Output Dual USB Car Charger

Two problems arise, The stock panel around the radio doesnt have enough free room for the tablet + the equalizer.

I want to make a copy of the panel, remove the buttons and 12v plug on top and relocate them to the glove box. Move the double din slot towards the top which free's up room below it for the equalizer.
I am not sure how to make a copy of the stock piece, was looking at making a copy of it and using fiberglass to try to make it as close as possible, or I've seen the plastic epoxy that people use to build stuff, could I just fill in the slots and cut out the holes where I want?

Two, I havnt done much stereo wiring work, is there a way to hook up the equalizer RCA outputs to the stock harness, or would buying new speakers/amp's with RCA in's be a better option?