Incidents in which police detect the presence of drugs while conducting a traffic stop are not uncommon. However, police do not automatically have the right to search a person or a vehicle after a traffic stop. An officer must have probable cause to conduct a search.
If a police officer asks to search your vehicle, then you have the right to decline the search. Police must then obtain a search warrant to look through your property. The situation is different if an officer sees a weapon, drugs or drug paraphernalia in plain view. If that is the case, then probable cause may be established, and police may search an individual's property.