What’s this part called?! I’m losing my mind

I bought this cap 2nd hand from some guy. He self tapped screws in and broke and cracked this plastic piece on the cap. BUT I don’t know what it would be called. It’s not just a rubber seal. It’s made of hard plastic with a seal underneath it. Please help!

 

It actually comes self tapped from the factory. But they screw they use seem to undo themselves. I had to replace a few of them in the last few months. As what it's called, recessed frame door skirt or valance. They are vehicle specific since they have to contour it the the shape of the tailgate. 2nd gen topper wont match perfectly with 3rd gen trucks. Your local dealer can order that for you. There should be a badge with a serial and model number inside to use as a reference.

 

It’s a 2nd gen truck with a 2nd gen topper so I should be good. But thank you so much. I’m going to see how much they’re running and see where I can get one! Thank you again!

 

NP, it should not be much. I just ordered a fold down window to replace my fixed window for $125.00. I assume it's going to be well under $100 maybe under $50.

 

You wouldn’t happen to know if it’s possible to replace that valence with an updated one? I have one just like OP w/ the 2 T-handles on each side of glass and want to add power locks to it, but can’t with t-handles, the newer caps have some sort of center handle with a cable that would allow a pop n lock to be attached. Sorry, OP, don’t mean to high jack thread.

 

The door is cap is cut differently. It's not interchangeable. But if your crafty enough, it can be redone. It's fiberglass after all.
Power lock not for the handle but can be done with two servos. Or one actuator with rods. I am still trying to figure that out myself, I have not put it down on my to do list yet, but I am getting the power tailgate lock and piggy back with that. I will order 2 additional actuator with the kit too so I can do all the install and mods at the same time. Or get all the wiring ready so I do not have to open the tailgate cover again.