Agree the specially formulated epoxies for plastic can work well.

Another option for dash parts is plastic welding. I had several cracked Challenger dash trim parts and sent them to "Mr G" in Texas. He welded them up and restored correct grain where necessary. Good repair and durable so far (about 2 years).

Here's a link to a thread I did a while back on a plastic dash fix, some other members had some good ideas, also.
Barracuda Plastic Dash Repair/Modification
If it's plastic, it's fixable...just takes patience. Good Luck!