The gun was in fact registered to Berry and he had a license to carry but according to PA law a license to carry does not allow you to carry in a vehicle.
This is a different animal. If he owns the car, then it is legal according to the US constitution. If he rented, or the car belongs to someone else, he could be breaking the law by carrying in a vehicle.
Search and seizure..... most states have almost instantaneous approval for warrants...ie they have a judge on call and they can now print the warrant in the police vehicle. So if the officer wants the evidence collected to stick in court, he probably should get a warrant. A good lawyer will get any evidence collected at a stop thrown out.
Brandishing a firearm is different state to state. In colorado, we have open carry laws so seeing a holstered weapon isn't brandishing. If you remove it and point, it is felony harassment with intent. In some states with no open carry law, it is a fcrime to be seen with even a holstered weapon. I know in Colorado there is a distinction in the law. If I'm a concealed carry guy and get in an altercation and "show" the gun by lifting my shirt...that is felony brandishinig. If I reach up to grab a box on a shelf and someone sees my weapon in a walmart, I can be charged with disturbing the peace. I would venture to say in most states there are small distinctions in the laws as well.