I have cracked one of the important tabs on my AW11 dash cover while dismantling it the other day, so I had to figure out how to fix it. Google came up with good hints, that ABS dissolves in acetone. Which is good because that way, you can melt it and glue together. The thing is, that if you melt the crack surface too much, you'll distort the original shape. So the ideal solution is to make your own molten ABS glue. You can either melt some old interior OR you can use LEGO bricks! Right, LEGO is made of ABS, so i reached out into my Technic box and pulled out a nice small black brick which I thought no one will ever miss (note: some bricks and pins don't melt at all, they just fall apart in acetone).
Unfortunately, I haven't taken any pics of my masterpiece but the dash cover holds as hell! I have, however, been melting another brick in order to fix and reinforce a cracked heater control from my Celica.
After the "sacrifice" material started to get gooey, I have picked some of it with a toothpick and started filling the empty area to reinforce it. Looks a bit rough at this point.
Then, I have grabbed an ear tampon, dipped it in acetone and smoothened the surroundings with it. It remelts some or the edgy bits and fuses everything together. Absolutely unnecessary if you are not into aesthetics :D
The dash repair wasn't this clean because I was adding layers of ABS plastics all around the crack line to reinforce the tab as much as i could, even gluing the holed metal strip onto the tab.
With a bit of practice, many cracked parts can be fixed. No need to search egay and breakers for bits