installing side mirrors

[GreenFish]

ok I got me a nice set of 70 ralley mirrors. I got my driver's on but it already had the little top hat looking nuts in the door. I am going to do the passenger side and i am wondering how those nuts stay in the door without pulling out. Do the screws make them expand out a little keeping them in or something like that???

It looks now that if i mount the mirror the nuts and the mirror will come out, but this is not the case with the driver side.
Can someone clue me in?

[74chall]

There is a special tool that inserts those threaded inserts into your door and mushrooms the back against the inner door skin. I just had to do that to my car, dont know where to get the tool, got it from my dad b/c hes a tool distributor.

[GreenFish]

I figured it was something like that.. can you try and find out where i can get one?

[GreenFish]

i figured it out..   those things are called "rivet nuts"  or "expanding nuts"  they can be installed with a tool that is basicly a rivet gun. Harbor freight sells one for $12 , Incase anyone else needs one this is the part number for harbor freight  30769-2VGA

Thanks 74Chall