Another source might be Eastwood Automotive.
http://www.eastwoodcompany.com/
They have some dash repair kits and many colors of vinyl paint to
match your exisitng interior. They show using the Urethane foam
in a can to fill the big cracks up, then using some vinyl patch and
texture paper to match the existing texture. Their kit has a modified
soldering iron to cure it. This like might work, not sure:
I like that idea. I used Urethane foam to repair my cracked console
top, and it worked well. It would have worked even better if I had used
the foam that dries more solidly. I didn't know there were at least two
kinds until a shower refinisher was using it to make sure the the
bottom of our shower didn't move around.