Under what circumstances a passenger needs to identity themselves differs significantly from state to state. Also, neither Brendlin v. CA or AR v. Johnson talk about identification requirements, so I'm not sure what you're thinking there. Maybe you're confusing it with exiting the car?

And before someone says "but the Supreme Court overrules the states", no it doesn't. Many state courts have found that their state constitutions grant their citizens more rights than the US Constitution in various circumstances.