[mefdinkins]

The Fourth Amendment protects people from unreasonable searches and seizures. The requirement for a warrant and probable cause flow from the Fourth Amendment. Warrantless arrests are generally permissible, warrantless searches are disfavored and are per se unreasonable subject only to a few specifically established and well-delineated exceptions.

One of those exceptions is the 'automobile exception'. When police have probable cause to believe that an automobile contains the fruits, instrumentalities or evidence of crime, they may search the vehicle without a warrant. The exception turns on the ready mobility of vehicles, and on the presence of the vehicle in a setting that objectively indicates that the vehicle is being used for transportation. Since vehicles can drive away, search is allowed without waiting for a warrant. Additionally, government regulates cars with licensing etc., so individuals have less expectation of privacy in a vehicle.

There are other circumstances where 'warrantless searches' are not violative of the U.S. Constitution. Many of you have cited the 'plain view' exception etc.

The US Constitution in some cases serves as a floor or ceiling for what is lawful/unlawful. In this case it seems that PA had rules that protected individual's privacy beyond what was required by the US Constitution. It looks as though PA now curtailed that 'privacy' to be more in line with other states.