no but i know what you're talkin about, i tried those on the flare to fenderwell holes and they worked, but not well, they wouldn't hold the tension
what im talkin about as far as the push pin type, is a 7/16ths version of the reuseable rivets that hold our fascia on, the feathered type that you just push in are called body pannel retainers or something of that nature
the kind i used have a wide washer lookin piece with a split rivet that you press through the holes, then press in the plastic pin and it spreads and holds the rivet part out and if you need to remove the rivet you grab the pin and pull it out and then lever the washer part up and it comes back out
the square ones that go into the fender itself have 2 serrated legs that protrude back towards the flare and you have to squeeze them together someway or another to get them to let go
if you've ever had the grill off you may have noticed some push pin rivets holding the fascia on, like 7 of them, i think they're 1/4 inch'ers
i also tried the 1/4 screw down rivets and they were simply too small for holding on the flares, the 7/16 size is perfect though
the 7/16'ers look like this installed
i think you were thinkin i meant these
here's the 7/16 push pin rivets uninstalled
OEM they use a non-reuseable plastic rivet that you have to drill out, or cut the head off of, or both in order to remove