I have a marble rolling sound behind the front row seats. My car is in service currently and their first search they didn’t find anything so they said they have to tear apart further which increases my service fee. I assume they’re going to find a nut or something that’s been rolling around in there and then I wouldn’t have any cost because it will be covered under warranty, but they said if it’s anything else that is at my expense of $500 what are your thoughts? I don’t see it being anything other than a part from the car. But the service tech is making me believe otherwise, I just don’t know if I should have them to diagnose it or not.