First off, you need to admit and acknowledge that a car, especially a common car like a Mustang GT is not and will never be an 'investment'.
Second, while I feel you are right in expecting to send your car to the dealer's body shop and receive it back undamaged, I think you are going overboard with the dramatics of the paint 'never being right again'. A good body shop can repair a car to showroom condition, with no issue.
Third, in less than a month of owning it, you have put 700 miles on it. That equates to 8-10,000 miles a year. That's basically daily driver status. If you think you're going to put 10K miles a year on a car and not pick up dings and scratches, you are severely mistaken. So if the car is going to receive dings and scratches over the course of the next year, whatever issue that may exist in your head regarding the paint not matching will be moot.
Fourth, the dealer is only on the hook to 'make you whole'. That means restoring your used 700 mile 2014 Mustang GT, to the condition it was in when it rolled into the body shop. They will not and you cannot make them switch out your car for a brand new car. Most reasonable people will take as fact that a professional body shop will be able to restore light damage to a car to showroom condition. So their offer to repaint the door is a valid one.
I wish you the best of luck in getting the situation resolved to your satisfaction. But I think you should establish reasonable expectations and allow the dealer a chance to make things right for you.
Not real sure what side of the bed you woke up on but yes, it will be an investment so long as I take care of it. Any car would be.
They even admitted tonight went I went back that any paint job will never be as good as the factory..
Let me be more specific. I got the car April 21st, signed for delivery on the 26th. The car had 31 miles on it.. The dealership put about 10 miles on it. And I have driven it to that dealership back and forth about 5 times now at a total of 14 miles round trip each time. Not real sure if you saw I lived in Chicago, IL but I am assuming you are smart enough to know I will not be driving it in the winter and it is currently my daily driver because it's gorgeous weather out right now.
And, part of making it whole is also making the mind whole, wouldn't you say? After all, I did end up spending $36K on the car after all the warranties and added 'protection' options I took.
Lastly, I neglected to mention the original window on the passenger side door which was scratched. That, I noticed off the bat and they gave me one of those 'we owe you' vouchers before I even signed for the car.. And I did allow them the opportunity to make it right. They replaced it with an after market safelite auto glass window. And, since the 'we owe you..' sticker only said, 'will replace passenger side window', I had to fight them tooth and nail to make it a Ford OEM window. This dealership by the name of Golf Mill Ford in Niles, IL has failed from GO.