I have a 2003 Hyundai Elantra. The remote locks the doors but sometimes it won't unlock the doors. I have to go to the passenger side, press lock on the remote, then press unlock (I can hear the 'clicks' for lock and unlock) and then use the key to open, climb through and unlock the driver's door. At one point it seem to help if I used the key and opened the trunk. The other doors will not unlock with the key. I replaced the remote batteries and even tried another remote. Same results. Happens intermittenly. Haven't figured out a pattern except seems to happen at worst possible times (dark parking lots late at night - not necessarily cold nights, when carrying lots of groceries or when I am in a hurry. Go figure - haha Thanks for your help.