What held the original panels on? metal clips, nylon pins, shoe tacks?

a tip for getting the location of the holes,if you have your old door panels, strip them down to just the backing board so you "clip Holes" are visible on both sides, match up the old panel to the new panel and trace the hole locations onto the back of the new panel being careful that your lined up and the panel wont move, you can tape them together with some painters tape on all 4 corners "on the angle" OR you can try putting your clips into the door and attach some two sided tape onto the clips "lightly" then carefully place your door panel on the door where it should be located And press firmly all around the door so the two sided tape will stick to the back of the door panel and it will also leave an imprint on the two sided tape where your clips would be. You cab put anything on to the clips that will transfer the location. To cut the location into the panel you need to be very careful with a sharp knife/blade if you go to an art supply store they have perfect detail cutting tools . Don't press too hard, trace the location with you knife and then sorta scratch off a layer of the impression bit by bit but don't cut in to far. I hope this gives you a little help.

second part of this install, beacause i had no interior when i bought the car i'm a little confused with rear panels, i see the screw holes for upper molding, but nothing else! what holds them in place ?