This is from another site...I think the body panel is ABS
"Ordinary hardware store ABS cement (a true CAPP solution) makes for an excellent bonding agent for the ABS body work. Just don't allow it onto finish surfaces and it will mend a crack nicely. To form a fillet, you can mix ground or shaved ABS scraps with ABS cement to form a thick slurry, then apply the slurry to build a raised structure.
I learned about ABS cement after I spent many hours with auto store plastic repair epoxy restoring the mounting lugs that I crumbled with LocTite. By the way, NEVER use LocTite on any fasteners that can contact ABS. The epoxy stuff is strong and will form a fillet, but it takes a long time to cure and is thus more difficult to work with than ABS cement. It also never really "welds" the ABS together like ABS cement does."