This is the first time this has happened.
Unable to open trunk. Is there another way to open? on 2004 Kia Amanti
Mine is the 07, so I'm not 100% sure if they are the same. You say it won't open, I'm assuming you are pulling the tab on the drivers' door and nothing is happening. Open the glove box and make sure the black "valet" button isn't pushed in, it will disable the door tab if it's in (I bumped it before accidentally, felt pretty silly). The second thing to try is the trunk button on the fob. If that fails, there is a place to insert the key manually. Look under the lip by the license plate, by the right license plate light. There should be a hole to insert your key. Hope this helps.
I have a 2004_Amanti. As mentioned above with a 2007 Amanti, there is a keyhole under lip of trunk licence
you could try to open it from the inside
Try the key , instead of the remote?