NHTSA Complaint #11447545 — 2016 FORD MUSTANG

I would like to file a complaint against Ford in regards to a door latch issue with my 2016 Mustang convertible. Starting in April 2021, the passenger side door will become unlatched on it's own while driving even with doors locked. It doesn't open entirely but enough to trip "door ajar" light and interior lights. Since that time in April it happened in June of 2021 and again in August after which I took car to a dealer. Door came unlatched at normal speeds between 40 and 60 mph. The car is under an extended warranty from Ford and the car now has approximately 37,000 miles on it. I am the original owner. The dealer kept car for about a weeks time and said they could not duplicate it. They told me warranty wouldn't honor it since they couldn't duplicate the issue and it would cost around $600 to fix possible issues. They asked me several questions implying I was imagining it or I didn't know what I was talking about. I've been driving for about 50 years. Since August, it has happened 2 more times, once at highway speed on 10/17/21 and again yesterday, 01/11/21 also at highway speed. This time my son was sitting in passenger seat. He is a Ford trained mechanic although he doesn't work for Ford but works on Ford police fleet cars. I do believe this is a safety issue but Ford will not address the issue. I took it to Ford corporate and they backed the dealer. I believe it will only get worse as time progresses. Wouldn't cover under warranty but if I wanted to pay they would do whatever I wanted them to do.