I believe it was supposed to be there as a transition to the door. If you run your hand from the depresion forward it smooths right into the door surface. Not to mention that it's unlikely that the mistake would have been made on both sides of the car. It used to be the last thing I noticed on a car, now it's the first thing I look for, if they aren't there you can be fairly certain that there's mud in the panel to fill it