Engine Undertray.

Originally Posted by RonZwanson

As everyone else has said, your car will run fine, but I'd replace it to protect all the components under your car from road gunk and also any potential damage. You never know when you're gonna be stuck behind a work truck that's dropping stuff all over the road.

If you do, go for the aluminum undershroud from Zspeed. I have one. Much nicer than the plastic one, and probably cheaper than what the dealership would charge you.