Door locks don't actually do what they are supposed to do. I found that out when my friend opened the door as a joke on a residential street a while back. When put into Drive, in motion, the locks flip to signal that they are locked but say if someone were to pull on the handle, it would still open. I checked all four doors, and they behave like this. I then compared it to my other vehicle, which did not act like this. In other words, you have to flip the tab to open the door. With the Elantra, however, you just pull on the handle, and it opens. I have yet to bring it up to the attention of my dealership. There were no warning lamps, messages, or other symptoms of the problem prior to the failure.