ttocs, thank you for the suggestion. I removed the door panels, found two strategic locations to install screws in the lower carpeted area, and measured how long of screws to use - 3” long if anyone needs to do this as well. Installing the screws over the top of the carpet you could still see the screw heads - the carpet pile is too thin to hide the screw head. Functionally it works but I wanted the screws hidden. I used a flat head screwdriver to pull back the carpet where the screws would go and installed them under the carpet. Served the purpose of holding the bottom of the door panel to the door perfectly. No more door panel slapping the door when the door is closed.
Now, while I have no intention of ever selling my car - what’s that old saying, we’re just caretakers of these cars for the next caretaker or something? The next guy that gets the car is going to be scratching his head figuring out how the door panel comes off.