Some commentary:
Do you ride with your gun under you thigh while driving?
My preference is to keep the firearm in its holster at 4 o'clock while driving. I can still access the gun if necessary from this position. A shoulder holster is often better and more comfortable for long trips.
Also, consider these thoughts. If you have a collision or even if you are forced to brake hard, an unrestrained gun might become a loose object in the cab. If it lands down by the foot pedals it'll be difficult to recover easily. It can end up in the passenger footwell, far out of reach. There is also a remote chance it could discharge.
If that's not enough, consider the situation where the gun is now off-body (under thigh, between seat & console, etc.) and you find your car blocked from moving and one or more assailants fire on you. If you exit the vehicle rapidly your weapon may remain inside the cab. This is not good for cats. Keep it on your person.
Do you leave one gun in the car that you can easily reach and carry a second one on your person?
In order for me to do this and feel comfortable about it, the 2nd gun stashed in the car would have to be in some sort of sturdy locking container and the car equipped with an alarm. Here you run the risk of someone burglarizing the car while you are elsewhere.
Do you use FMJ’s to get better accuracy and penetration through the windscreen & windows?
This seems to imply that one will change ammuntion before exiting the vehicle and change back to FMJ's when you return. That's a lot of unnecessary weapons handling in a given day.
While in my vehicle, I am in control of a 5267 pound blunt instrument. With 4-wheel drive. There's also a 300 h.p. engine to help get me out of the kill zone. These are my first and best options. If someone is approaching and begins to wave a gun around or shoot at me, damaging other vehicles in traffic will be a tertiary concern. My first concern will be getting away from the lunatic. My second worry will be contacting emergency services for help.
If a deadly threat appears at either door, I'm shooting through the window, not the door. That's one piece of tempered glass (which shatters) to deal with, versus two layers of sheet metal, possibly a side-impact beam, window glass that extends below the doorsill, window cranks, electric motors, linkages, etc.
When using a motor vehicle as cover, put the engine between you and the threat. Position yourself behind a tire/wheel for added protection. If not near the engine, then positioning yourself behind the tire/wheel is better. Remember to keep your head down too. Vehicle doors are not bullet proof, but using them like police do gives you a chance that the bullet will be stopped or slowed enough to prevent a lethal injury. Just remember that your shins and feet are exposed (help counter that by cranking your front wheels to the left).
If attacked by several persons while in traffic, use the Secret Service technique - MOVE. Push other cars if necessary or drive on the sidewalk, opposite lanes, back up, make a u-turn... but MOVE. Sitting there is likely to get you killed.
