Next week, the Supreme Court of the United States will hear Byrd v. United States, No. 16-1371. The case considers whether a driver has a reasonable expectation of privacy in a rental car when he has the renter's permission to drive the car but is not listed as an authorized driver on the rental agreement.
Letting a family member or friend drive a car you have rented can be a breach of the rental contract (if that person is not listed as an authorized driver), but it is not a crime, and it should not serve to forfeit the Fourth Amendment rights of the driver. This is an interesting case, and we will report back when the decision is issued.