A police officer may not conduct a suspicionless and warrantless search of a car if the driver has a reasonable expectation of privacy in the car–i.e., an expectation of privacy that society accepts as reasonable. Does a driver have 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.
Byrd’s girlfriend rented a car for him and gave him permission to use it, but he wasn’t listed on the rental agreement. Without a warrant or probable cause, troopers searched the car and found 49 bricks of heroin and body armor. The question is whether Byrd had an expectation of privacy in the rental car. There is an irreconcilable split among the circuits and some state high courts over this issue. The 8th and 9th Circuits, Nebraska, New Mexico, Texas, and Oklahoma hold that if the renter gave the driver permission to use the car, then the driver has an expectation of privacy. The 3rd, 4th, 5th and 10th Circuits and Montana and Arkansas hold that the driver has no expectation of privacy, though their reasons vary. See cases cites here. Wisconsin isn’t listed as having decided this precise question. If you’ve got the problem in a case right now, be sure to preserve it. There’s plenty of good legal research in the cert petition and amicus briefs for you to cite.