Hey, I even have mine with me in the house.
Besides, leaving it in a car, where a thief can see it, is asking for trouble. I also hide my GPS.
Out of sight, out of mind. I dont trust anyone! my phone is with me 24/7. Even at work if i go to the fax machine i'll unplug it if charging and bring it with me. The fax machine is about 20' away. I think its me being paranoid but still if it makes me feel better knowing no one can take my phone then so be it!