This case was significant in that it helped to define what the police may and may not do in terms of searching cars and passengers during traffic stops.
In this case, Wilson was a passenger in a car that got pulled over. The officers ordered him out of the car. When he complied, a bag of cocaine fell on the ground and Wilson was arrested. He claimed the police had no right to make him exit the vehicle during a routine traffic stop since he was only a passenger. The Supreme Court said that the police do have the right to require passengers to exit the vehicle. The reason for this is that the need to protect the safety of the officer overrides the invasion of the passengers' liberty.