Loose door panels , 1995 xj6 Vanden Plas

My preowned car was damaged during a Sony stereo and speakers replacement before my taking over ownership.
Every door panel is flopping about. Pretty certain the fasteners were pulled loose from the panel. What have others done to correct the situation?
Are new fasteners available, how are they reattached. Does the receiver plug in the door need to be replaced as well and available from?
I have had this problem with Two Volkswagens and never did find parts or a solution. A few times i tried epoxy to hold them on where they tore off but thats hit and miss.
My glovebox fell off last week and now that plastic plug is being epoxy glued back in which brought to mind all the panels that need fixing too. Looked like it too had been broken once before.
Thanks in advance

You can buy most female and male fastener clips from Amazon. Just search for “panel fasteners.”

Thanks, theres lots of fasteners there, also at auto parts stores too. Im hoping to find someone who has actually installed new ones, methods important to me. I have not found a satisfactory repair to this on multiple cars now.
I made copper clips for a New Beetle, wont work on the Jaguar tho.
Ideally one could screw thru the damn panel and forget the problem. Engineering failure IMHO