An interesting Kozinski opinion
Here, in pdf.
Basically, police had probable cause to search a car, which was being used for drug transport. But they didn't want to tip off the owner just yet. So one officer faked being a drunk driver and bumped his car. Other officers "arrested" him. The driver and girlfriend were asked to come to a squad car to be interviewed, and during that another officer played car thief and "stole" their car. Police went in supposed pursuit, returned to say he'd gotten away. Police then got a warrant, searched it, and found narcotics.
The opinion determines this was a reasonable, if quite novel search. Police could have seized the car without a warrant -- it's a car, and they had probable cause. They carefully bumped his car in the faked accident. They returned all the property they could (claiming the thief had thrown it out the window during the pursuit -- you wonder that the suspect didn't think that a bit strange, was the driver thinking that he'd go faster if he lightened the car by a purse?).
[via the Volokh Conspiracy]