The large interior plastic trim piece that covers the bottom of my wagon's liftgate all the way across below the rear window keeps popping out of its mountings every time I close the gate, even if I close it gently. I only seem to be able to snap one of the outboard mountings back into place, although the inboard mountings look undamaged. Anybody know anything about this? Suggestions to get the other two mountings to snap into place without breaking something? I already tried removing the shroud around the high-mounted brake light to see if that would help.