As can be seen in the photo this is a clamp for holding the elasticated straps. The photo shows an original (at the top) and the printed part below. This is not an exact replica but a fully functional alternative. It comes in two parts that are push-fit and can be glued.

When installing there is a notch to ensure correct orientation.

The part is suitable for a Series 1 BMW and I believe, but have not verified, other models