311 is pretty useless. Call 266-1234 and report a suspicious auto... maybe have a look at the door locks of the car, look inside at the ignition, if anything looks tampered with, it's likely stolen.
If it's a dodge neon, or honda civic, I can almost guarantee it's stolen.
Get the plate, call the police non-emergency number I mentioned above, and if they will likely at least contact the owner to have it moved if it's not stolen.
Hope that helps...
Just because it happened to you, doesn't make it interesting.