I bought a tube of Flex-Seal as seen on TV
and bonded my radio surround vinyl and auxiliary gauge pod back. I used a strip of wood along the sides to press the vinyl so it would be flat with no clamp dimples. You have to remove the loose foam rubber inside for a more effective and lasting bond.
Next project this fall/winter is to remove the center console and bond the areas along the sides where it's turned loose.
Flex Seal is supposed to be paintable, too. I plan to experiment with my old 86 dash which is pretty well broken up. Fill some of the cracks and spray over it with the Fiero Store dash paints to see how it looks.