...written down on something in a vehicle. If someone stole one of my vehicles, they would not find my phone number. They could find the registration, as you said - but that's only going to give them my name and address. We don't have a home phone number. But I suppose if you have a listed home number, someone could do a Google search with name/address like you suggested and find a phone number.

And I agree - it makes no sense that the thief was able to drive off with the vehicle without having the key in the vehicle. My guess is that it was not a factory-installed remote start system, and the doors were left unlocked by the owner.