State v. Webster
In State v. Webster, 170 Ariz. 372, 824 P.2d 768 (Ariz. App. 1991), a divided division of the Arizona Court of Appeals reasoned that an order directing a passenger to return to a car stopped for a traffic violation imposes no greater intrusion on the passenger's freedom than an order directing a passenger inside a stopped car to get out.
In addition, the court was persuaded that the interest in protecting the officer does not dissipate when a passenger gets out of a stopped car:
"We cannot allow the officer's safety to depend on how fast the driver and passenger can get out of the vehicle after it has been stopped. Ordering the occupants back into the vehicle does no more than establish the status quo at the time of the stop. To hold otherwise could well lead to the unnecessary death of an officer, gunned down by those walking away who suddenly turn and fire or who circle behind the officer, either assaulting or killing him while he is talking to the driver." (State v. Webster, supra, 170 Ariz. at 374, 824 P.2d at 770.)