Most states make it illegal for passengers in a car or other vehicle to consume or drink alcohol as a passenger.
Even though the passenger is not the one driving it's still illegal for the passenger to drink alcohol because the driver could also be drinking although most times they are not.
So most states do make it illegal for the passengers to consume alcohol.
However the passengers or passenger can be drunk and riding with a sober driver which is legal but if you get pulled over with a drunk passenger then they may want to do a sober test on the driver as well to ensure you're not drunk.
If you're not drunk or have not drank any alcohol then submitting to the test is what you should do.
If caught as a passenger drinking then the driver and passenger can be charged with an open container charge.
The only exception to a passenger in a car drinking is in a Limo.
Yes Limos can serve alcohol to the passengers.
However to be able to serve alcohol in a limo you need and alcohol serving license along with your license for the Limo.
The reason Limos can serve alcohol to passengers in the limo is there's a window in the limo that separates the drivers compartment from the passengers.
So the passengers can drink alcohol while the limo driver does the driving.
The people in the limo can get drunk as long as the limo driver does not drink any alcohol and any professional limo driver would not drink alcohol while driving.
I've drank alcohol in a limo before for a party and it was legal to do so.