There is a seperate bottom door seal but it doesn't go on your door, it screws to the cab floor and seals against the bottom of the door a few inches up.
The vendors usually call the seal that goes on the door a "door seal". The seal that goes around the door opening on the cab is called "windlace". There is also a lower cab windlace that is attached to the cab with a retainer across the floor at the door opening (most likely the piece that obrien is describing).
