Innocent Fool

I've mixed up 2 part epoxy, put it in a syringe with a needle and injected it into the crack.

The key thing is you want the the epoxy IN the crack and not ON the surface. Make sure you put masking tape on both sides of the crack and trim it with a knife to expose the cracked area and protect the surface. When injecting don't use too much epoxy because it will get squeezed out later.

Flex the panel to close the gap (as best you can) and HOLD it there! When the panel is flexed the gap will close and the extra epoxy will be squeezed out. Pull the masking tape off when the epoxy is still wet (to remove the extra epoxy) Keep the panel held in place when removing the tape.

Make sure you keep the crack closed while the epoxy sets. I used clear 5 minute epoxy so I didn't have to hold the panel in place all day but it still seemed long enough.

Anyway, When I got done the crack stayed closed and it was hard to see where it was. I'd say it was about a 99% job. It's been a while since I fixed it and I haven't had any issues yet. Crack hasn't re-opened and you can barely tell it was there

Note that the crack in my dash was fairly new and it closed really well when flexing the panel. If the crack is old the edges may curl and it may not close as well as it could

Try at your own risk and good luck