97 Cadillac Deville your trunk does not pull down has stopped working so it is no longer flush when locks you heard that this caused by slamming the closed breaking a plastic piece?

Yes, it's a common problem on 97 Cadillac DeVille (and other GM vehicles of that era) that slamming the trunk lid can break a plastic piece in the trunk lid release mechanism. This plastic part is often a relatively fragile latch or striker assembly. When broken, the trunk lid won't sit flush and the mechanism will likely not work properly. The repair usually involves replacing this broken plastic part. You might be able to find the part at a junkyard or an auto parts store specializing in older vehicles. You'll need to find a diagram or look at the mechanism closely to identify the broken piece.