You're going to have to specify left or right. The "Passenger side" can be subjective to which side the steering wheel is on, and you could confuse people and/or end up with the wrong part. Seeing that you're in the U.S. I'm going to assume that you have a left hand drive car. As you're sitting in the drivers seat looking out of the windshield is the relative position in which one determines left or right. In light of the aforementioned, it would seem that you're after a right side grill bar. The part number is 113-888-02-21. If you end up having to buy a new one they are still available new from Mercedes. It lists for $368 and wholesales for $267.
