If you are referring to the front bumper cover there are many options. I believe these were urethane, and I've had good luck with the Lord Fusor products. There is a backing material that looks like mesh that you must use for strength. Bondo or fiberglass would only be temporary at best.
JC the stuff you want to use is SEM 39767 Problem Plastic Repair Material. Sets up fast and if applid to correctly prepped base bonds well to a variety of plastics. You'll also need an application gun to use it and it's a good idea to get some extra nozzles. Evercoat nozzles work with SEM 2 parts as well. SEM has some helpful videos online as well. Google "SEM 39767" Other products like Lord Fusor are excellent as well. My favorite though is the SEM.