What it used to look like:
What it looks like now (taken from below, looking up toward the radiator):
How can I fix this? the broken surfaces need to be strong against pulling-apart forces, so I guess simple glue or tape won't cut it. I was thinking of maybe drilling holes on each side and lacing the breaks together with wire or plastic zip ties. Appearance is unimportant, as this is underneath the car and not normally visible.