In the case of Maryland v. Kevin Darnell Dyson in 1998, the U.S Supreme Court ruled that police officers do not need a warrant to search a car if they have probable cause to believe it contains illegal substances or evidence of crime. The decision came after an officer stopped Dyson's vehicle for speeding and noticed large amounts of cash inside. Based on his training and experience, he suspected drug activity and searched the car without obtaining a warrant first, finding cocaine in its trunk. The Maryland Court of Special Appeals later suppressed this evidence arguing that there was no exigency justifying a warrantless search despite probable cause. However, the Supreme Court reversed this decision stating that under their precedent (the automobile exception), if police have probable cause to believe there is contraband in a vehicle moved on public roads, it can be searched immediately without further justification needed.

In the case of Maryland v. Kevin Darnell Dyson, 1998, the dissenting opinion argued that police officers should not be allowed to search a vehicle without a warrant just because they believe it contains contraband. The dissenters felt this was an overreach of power and violated the Fourth Amendment's protection against unreasonable searches and seizures. They believed that probable cause alone is insufficient for such invasive action; instead, there must also exist exigent circumstances or immediate danger to justify bypassing obtaining a warrant first. In their view, allowing such searches based on probable cause alone would erode citizens' constitutional rights and give law enforcement too much discretionary power in deciding when to conduct warrantless searches.