When I lived in San Francisco, a thief stole my car stereo. It must have required a lot of squirming around to remove the stereo, because his wallet (with driver's license) fell onto the floor in front of the front passenger seat. I found it the next morning. The police came by and had a good laugh while they took my info. While we were talking, a neighbor walked up and told the police that she had watched the theft from her living room window at 2 a.m. She provided a complete description of the thieves -- young Asian males -- and the license number of the car they had been driving.
The father of the kid who dropped the wallet eventually paid for my replacement stereo.
All in all, a somewhat less than perfect crime.