I just got the 2 brackets for this piece and while the large bracket that mounts closer toward the front of the car is pretty stable (had to move a few wires out of the way which was a pain) the small bracket (nearest the rear of the car) is pretty wobbly. The pin that keeps it in place seems to not be expanding the plastic parts enough for the bracket to sit flush with the metal bodywork. Is this normal? What are the experiences out there?