Another factor is who is/isn't with you. If your family is in the car while you are outside the car and the carjacker is willing to let them exit the vehicle, I would continue to comply. If the carjacker is not willing to let me remove my family then compliance isn't something I can consider.
I have done the carjacking scenario and a number of other scenarios in force on force, scenario based training events. To echo some comments above, beating a drawn weapon is extremely difficult. I know some people that are unwilling to consider compliance regardless of the scenario. I've seen firsthand in that training how that can go.
