I keep a CRKT Stiff KISS mounted under my dash to the rightof my steering wheel. Just the para-wrapped handle sticks out enough to grasp,and most people who ride with me never even notice it. Its purely for emergency backup- car accident, or whatever.
I'm not a self-defesetype, but I am paranoid about not being able to get out of my car after an accident.
My advice to you would beto makesure you mount it very near to hand; If your concern is, say slashing seatbelts, then you need to have it close enough to grab when you might be injured and can't move much. For me, that mean mounting to my right, because when you're driving, your left side is what's going to get hit.
I'm not adept enough in self-defence to discuss placement of the knife for personl protection, but I'd assume what I said above still holds. Some guy reaching into your window could imiobilize your draw stroke. Perhaps between seats or some sort of roofmount?
Gollnick:Really great info in your post. You gave me a lot to think about there. In terms of legalities people, I know that a prosecutorcould get anyone convicted for concealed carry of something as simple as a nail file. But my fear of being trapped in a burning car with a broken arm (Much more likely cuz I drive a LOT) greatly outweighs my fear of arrest and prosecution for concealed carry (very unlikely cuz I'm a big teddy bear)