you can get into the car with the key in the drivers side door lock, just if you have an alarm fitted it'd go off. if you've deadlocked the car and your sat inside the vehicle, you cannot exit without the key, as the button on the driver's door is de activated as too are the door handles on the inside. no matter how much you pull them it won't unlock the car. (having said that if you've deactivated your deadlocks two presses of the lock button on your key fob, then if you pull twice on the door it'll open). hope this clears everything up, but like i said beforehand in another posting, if a thief wants to nick ya motor or steal something they'll get in no matter what. no car or house is 100% secure!