State police officers, armed with a valid warrant to arrest Peter Swope for the crime of defrauding the state welfare agency of $100,000, stopped Swope in his car on the Turnpike. He was taken into custody, and his auto was locked and left on the shoulder of the road. Later that day the state troopers returned and searched Swope's car. They located a plastic bag on the passenger seat, which they brought back to the station and opened to find a large quantity of illegal explosives. Although the welfare fraud charges have been dropped, the prosecution intends to use the explosives in an upcoming trial for possession of illegal explosives. Swope's counsel has filed a motion to suppress and has persuaded the court that because there was no probable cause to believe seizable items were present in the car, the search was unlawful. Is there any way the prosecution can nonetheless avoid suppression of the explosives? What if state police regulations require that vehicles of persons taken into custody on the open road be impounded and subjected to a prescribed inventory inspection?