This level of ignorance explains a lot about...ah, never mind. 

OK Rachael.  I think you're crazy.  I'm guessing you don't own a gun but I'm going to call the cops on you because you probably shouldn't be driving.  Officer Friendly stops by and he agrees that you're a little nuts so he decides to confiscate your car based on his spot assessment.  End of story and you never get it back. The cop also has the power to decide if you can be involuntarily indefinitely committed to a mental hospital.   You're cool with that right? 

Personally I'd rather have a judicial hearing to decide if I'm legally insane but your way sounds pretty awesome too.