If you find yourself pulled over by a Nevada police officer, the police are not violating your constitutional rights by telling you to exit your car. Irrespective of whether you think the traffic stop was justified, you are usually not within your rights to decline a police officer's order to exit your car.
We all remember the horrible July 2015 event that led to Sandra Bland dying in a Texas jail: The cop who pulled Bland over told her to get out of her car after she refused to extinguish her cigarette. Then when Bland declined to exit her vehicle, the cop forced her out. Legally, Bland was probably not within her rights to decline to exit the car.
The U.S. Supreme Court in Pennsylvania v. Mimms (434 U.S. 106 (1977)) held that police officers can order drivers to get out of their vehicles during lawful traffic stops. And in Maryland v. Wilson (519 U.S. 408 (1997)), the Court held that the officer can also order passengers to exit the car during a stop.
However, police are more restricted regarding Nevada search and seizure laws. If the cops overstep their constitutional bounds when searching your car, you can ask the court to "suppress" any evidence found from the illegal search. But if you agree ("consent") to a search, then any evidence found is fair game. That is why people should never consent to a vehicle search.
For California law, see our article What should I do if a California cop tells me to get out of my car during a traffic stop?