Part identification

[1973]

Hi i came across these, wondering if anyone knows what they are? It looks like a rivit, but the round nub at the end is part of the piece, and it has a bend on the other end

 

[Challenger RTA]

I cant say it is challenger part that I remember. I pretty much had everything apart at one time. The only thing I didn't take apart were the seats. They didn't need it. The end of it looks like a rivet. Or a stud from spot welding stud unused? But I don't know all parts from different years.