Ok so basically.
If you are in the vehicle with another criminal who has 2 or more stars and you are spotted by police, you should automatically receive a 2 star wanted level as well.
You know you are in the vehicle with another criminal and most of the time these white names decide to shoot at the cops anyways because they're "with their friend" so a wanted level should apply to them as well for riding in their vehicle.
This can be modified to only apply a 2 star wanted level if you are riding with a MW criminal and only apply 1 star wanted level if you are riding with a 5 or less star wanted criminal.