Mazda CX-9 2020 Problems
No car is perfect, but we've gathered everything relating to the Mazda CX-9 2020 reliability here to help you decide if it's a smart buy.
The passenger door hinge has been snapped off my 2020 Mazda CX-9 TC Sport
If the door flies open when you unlatch it, it sounds as though the problem might be with the check-strap, rather than the hinge. The check-strap has the job of limiting the amount the door can open and avoid it flinging into whatever is parked beside you. If the actual hinge was the problem, the door would almost certainly drop when you opened it, making it very difficult to close again.
In either case, though, it should be a pretty clear case of a legitimate warranty claim, and a 2020 Mazda is still well within the factory warranty period, regardless of whether you're the original owner or not.
Take the car straight back to the dealership you bought it from and there should be no arguing over having it fixed free of charge. I'm a bit surprised a car dealership would sell a car with this sort of problem, but it might simply be that the item was overlooked when the vehicle was being prepared for sale. The bottom line is that this is Mazda's problem, not yours and according to the warranty, it should be fixed for free. The only exception to that would be if the damaged part was caused by previous crash-damage, but even then, the second-hand car warranty offered by the dealer should cover such a pre-existing problem.