My '72 Dart has two plastic clips along the left edge of the headliner, which I think provide a place to store the shoulder belt when not in use. Can't think what else they might be for! I wear mine all the time anyway, so...

Anyhow, they buzz like a bee flew into my ear at exactly 55 mph... I can't figure out how to remove them so I can add some dampening material. Slide a screwdriver in there somewhere? shruggy I don't want to break them, they're probably $50 apiece...