When i first got the car, the back door behind the driver unlatched while i was driving. It did not open completely but it was still a concern.

It turns out that if one of the back doors is the last one to be closed then it requires extra force to close it. When i took it to the dealer, I was told it is because of the air pressure inside the car. Apparently it is designed to be air tight and closing the last door will always require more force.