Fiberglass over our plastic panels?

A few weeks ago i used this to repair a urethane bumper cover tear in the mounting ear. It cures very nicely, very hard yet flexible enough. Worked very well for my application. Supposed to beable to sand and print it. for $7 at your walmart, i'd give it shot. For the crack, I would glue the crack AND a reinforcing gusset on the back side so it doesn't spread any more.

https://www.jbweld.com/product/j-b-plastic-bonder-syringe