Name that fastener

Bodyperson said
If you are going to "use" the roof rack, the rubber well nuts will tear out if there is any uplift. Seen it first hand.

I have seen them used to hold on a rear bumper with a class 5 hitch... thank god the hitch never got used.
I seen em used to hold seats in.....

They aren't really load bearing.... that roof rack is a fine use but beyond that amount of load I would find another way to attach.

I have 4 different insert tools. Two like you mentioned and two rivet gun style. I mostly use the large rivet gun style by Astro.

I link it in a sec.

Astro Pneumatic - 13" Hand Rivet Nut Kit w/ Rivet Nut Assortment

If you have access to the back like in Princesses picture, double nut inside the car and a washer on top, then tighten the bolt will work in a pinch.