If a police officer pulls me over, can she frisk me or search my car?

Yes, if the officer has a reasonable suspicion you are armed and dangerous, she can frisk (pat down) you when you are pulled over for a traffic violation. Similarly, if the officer reasonably suspects that you are involved in criminal activity she can also perform a pat down. Assuming the police have probable cause -- a reasonable basis or justification to believe that you or your passengers are involved in criminal activity -- they can search your car and objects belonging to passengers.

If my car is towed and impounded, can the police search it?

Yes. If your car is impounded, the police are allowed to conduct a thorough search of it, including its trunk and any closed containers that they find inside. This is true even if your car was towed after you parked it illegally or if the police recover your car after it is stolen.

The police are required, however, to follow fair and standardized procedures when they search your car and may not stop you and impound your car simply to perform a search.