Question: Does an authorized driver of a rental car have a right to object to a police search of the car?

Answer: Yes, in many instances. 

The general rule with police searches is that the police need probable cause to search the interior of a house or car PROVIDED THAT the person involved has a “reasonable expectation of privacy” within that property. That is, a person who owns a car may object to a police search of the car. However someone who unlawfully stole or “borrowed” the car may not be able to object to a search on a theory that he or she had no reasonable expectation of privacy in someone else’s car.

A person who rents a car, and is on the rental agreement as an authorized driver, has a reasonable exception of privacy within that car. This means that the renter may object to a police search.

But what if that authorized driver permits a friend or family member to drive the car? Does that friend or family member have a reasonable expectation of privacy to object to a police search?

This was the issue facing the United States Supreme Court in a recent case. In Byrd v. United States, a lower court held that the driver — who had been granted permission to drive a rental car by the authorized driver — lacked a reasonable exception of privacy in the interior of the vehicle and, accordingly, could not object to a police search. 

The Supreme Court reversed the lower court holding that the mere fact that a driver is not listed on the rental agreement does not, in and of itself, defeat an otherwise reasonable expectation of privacy. 

This means that a person who legally borrows a rental car may be able to object to a police search.

It is important to remember that there are other reasons that the police may be able to search a car (for example, if they have a search warrant or where probable cause exists to believe that the driver has committed a crime). But the Supreme Court holding in Byrd makes it clear that simply because a person is driving a rental car does not give the police an automatic right to search the interior.