Here's what you need .
This is not crazyglue, but it binds plastic like crazy. You will need to use a plastic "bridge" inside the joint. I used a flat strip of vinyl cut from a piece of "J" channel for my backer.
The repair is far stronger than the original material alone, and absolutely invisible from the good side. My repair was on the inside control panel cover on my A/C. (same sort of plastic)
It takes 15minutes to hold and 24hrs to cure to full strength.