Just give them time. They've been traumatized by the long drive and then being placed in a new environment that smells different to them. It can take several days; just be patient. It sounds like you're doing the right thing by leaving them alone in a room together; it's much less traumatic for them to be in an enclosed space initially to get used to the change. Try to spend a little time with them, just quietly sitting in the room, not moving or attempting to catch or pet them. Let them come out on their own. They will, although it may take several days. Congratulations on your new babies and welcome to Pet Talk!