You should set up a recurring search on ebay for the vin and maybe for any combination of the words "blue" and "vehicross."

If he has the title, there is a decent chance that he will impersonate you and try selling it to a used car dealer in another state. I don't know how it works in California, but in Florida, the dealer doesn't have to register squat with the DMV until he sells the car, at which point the title transfer is recorded as going from the guy who sold it to the dealer to the guy who bought it from the dealer.

With so many used cars on ebay, there is a decent chance that if it ends up in the hands of a dealer, he'll put it on ebay, at which point you would automatically get an email from ebay telling you where your car is.

Sorry that I do not have any advice on how to make the police take you more seriously, do you know anyone in law enforcement personally that you can ask for a favor?