As you should expect the officer to be courteous, he or she appreciates your cooperation as well. You should remain in your vehicle and wait for the officer. Please turn down your radio and don't reach around for your paperwork. This only causes concern for the officer that you may be hiding something or reaching for a weapon.
Remember the officer has no idea who he/she is about to speak with. You should never exit your vehicle unless the officer requests that you do so. You know you are just on your way home from the supermarket, the officer does not.
Today's criminal does not have a certain "look." He or she can look like "the person next door" and the officer has no way of knowing if he/she is stopping a corporation executive officer late for a meeting, a parent picking up a sick child from school, or "the person next door" who just robbed a local bank.