Installing Emblem on Quarter Panel

I am finally getting around to replacing the Dart GT emblem that was broken on my quarter panel. The typical way to replace it would be to pull the rear seat and rear panel out and use push nuts from the back side of the emblem. However, that is obviously a pain in the butt. I have seen a different kind of "nut" that is pushed through the hole with the emblem pin and then flares out inside the fender to hold it in place. However, I am not sure what those are called or where I might find them. Anyone know where I might find that specific kind of fastener? Any information would be appreciated. Thanks.