Can everyone in the car be charged for drugs found in the car?

Possibly — and this happens routinely, which is why it's worth understanding how it's supposed to work.

Ownership is not the same as possession. In a jointly occupied vehicle, the State has to prove knowledge and control as to each individual person. It can't simply charge everyone and let the jury sort it out, though the arrest often looks that way.

When drugs are in a jointly occupied place, or in someone else's bag, additional evidence connecting a particular defendant becomes especially important. Confessions. Statements indicating a person knew the substance was there. DNA or fingerprints on a container. Proximity to that specific spot rather than to the vehicle generally.

Those things can support a conviction for one person even where someone else has admitted the drugs were theirs — which surprises people who assume an admission by one occupant clears the others. It doesn't automatically.