I would suggest getting some bondo (from autozone/home depot), and flush fill the sides of the lilliput to stream together with the dash. The bottom where it meets your AC controls, I'm not sure(you gatta do some artwork there), You can use bondo to make them look joint together.
Also realize that when you do this the front of the lilliput is fixed to the panel. So you would have to take the front cover off the screen, and remove the panel itself to do this work. When you are done, join in the other half of the lilliput from the back of the panel. The sticky in the fabrication thread shows how to do this. You do not need the foam(in his example).