Dear OP! I'm so thankful your post came up first on my google search while I was at a Shell near the airport frantically searching all over the car for the button and pressing and pulling at the gas door. I didn't allot too much time for getting gas so it was really stressful as each minute ticked by. I nearly gave up but pulled out my phone and googled "Where is Dodge Charger gas door button". I read your entire post and found the button.
My friend said, "American engineering at its finest!"