I feel that a person, not the subject of arrest, should be protected
by the 4th amendment if they choose to remain in their vehicle, even
if “ordered” to exit the vehicle by an officer.
The intuition is fine, but is basically incorrect.
I’m most interested to know:
How would a driver (1) Politely (2) determine if a given instruction
to exit the vehicle must be complied with, and (3) decline the
instruction without giving the officer “cause” or otherwise damaging a
From a practical perspective the only workable response is to comply. There are times when this is done without a reasonable suspicion (or in some cases probable cause) or other legal basis, but it is pretty much impossible for you to dispute this one the spot. Most of the time, the officer will have the legal authority to order you to leave the vehicle.
If they order you to exit the vehicle despite not having the legal authority to do so, the right course of action is to comply and then to file a complaint with the agency employing the officer or to bring a civil lawsuit against the officer.
There are good answers to a basically duplicate question at How can you tell if you have to follow a police officer's instructions?