My ex-girl friend has stolen my car. When I tried to report it to the Hayward Ca. Police dept. I was told that I had to send a certified letter to her last known mailing address, wait 10 days, and if no response I could then file a report. My question is, what do I do If I don't know her last mailing address and If I did, and she didn't sign for the letter. What is my recourse?