Do you think someone might have started to break into the car, then someone (maybe even cops) drove by, so they bolted? It sounds like they just started getting in there, but didn't have enough time to take anything REALLY worth taking, making it a rush job? That's the only thought that occurred to me.

 

ah, the ol' got-too-drunk-at-transit-and-had-to-pick-up-the-car-in-the-morning? i've done that before.