Hey, don't know if this is the appropriate section but it said exterior so what the hell.

Driving on the highway today, and down the road i see what seems to be a fairly small sized pinecone, normally I would try to swerve a bit to avoid having the thing underneath my car at all, but traffic was busy, and the two lanes were merging, so I had to drive over it. For a second, I thought I was driving Big Foot and the height of my car slipped my mind. Slowed down a bit, turns out it was a solid rock, a pretty damn big one. Heard a loud bang and a couple of thuds, and a couple seconds later I hear something that sounds like something is dragging on the ground. I pull over, and take a look underneath the car and sure enough, this rock has just ripped through this black cover type thing located right behind the engine and the front left wheel. This thing was completely in contact with the ground, and I noticed that the only thing that kept it on was 1 screw, so I took it out. Its about 1.5 feet in length, with the screw I removed on the triangle like end, the other end seems to be missing an entire section, I don't know if it flew off or its still held on by a screw.

Anybody know what this cover is, what it does, and if its safe to drive the car. Is it required or is it ok without it. Thanks for any help. =)