I think the "being found by a criminal" is your biggest hang up here. Other than that there a lots of good options given here.
I think if there is a criminal in your car, your probably facing a good chance that the whole car could be taken. If not than its probably a quick grab and go break in, and they're probably not gonna be checking every nook and cranny looking for hidden stuff. Your gonna have to compromise somewhere man.
If not, best of luck to ya. I can't believe I wasted the time to read all of this and reply. But I bet your gonna waste alot more searching for the perfect spot/setup and still compromise something you listed.