You never have to roll your window all the way down during a traffic stop.
When a police officer pulls you over all you need to do is roll the window down just a few inches which is enough to slide your drivers license, registration and insurance documents through to the office and allows you to converse with each other.
Unless you're suspected of a crime or a danger to someone or wanted the then police cannot force you to roll down your window.
Now if you're wanted for something and they find that out and you refuse to leave your vehicle and be arrested then they can break the window out to pull you out of the vehicle.
But just a normal traffic stop for a moving violation then no they cannot force you to roll your window down any further.