What is the name of this door hinge pin? Its hollow...?

I need to replace a door pin on my car door. But, when I look up parts for this, all I see are solid, brass looking door hinge pins - they look just like a hinge pin on a door for your house. This is NOT the part I'm looking for. There is another pin that looks hollow to me, which is connected to a a metal "arm" that extends into the door frame. I believe this arm is meant to keep the door from swinging open too far. So again, it's not the actual hinges for the door, its this pin that holds this arm to the door frame. What is this pin called so I can order one???

Thanks!