Suggestions: Separate carriers with food, water, and small litter boxes(aluminin pans work well) for Shadow and Callie. Let Whisper go back under the car seat again and...ear plugs for Sarah. Helps if they are leach trained and you can stop and walk em. Guess you know not to let them loose otherwise. Years ago before we were thirty years into cat and cat traveling behavior, my husband and son let one of ours out on the Alaskan Highway and it took them a day to locate her. She stayed with us after that for 18 years though. Oh, helps if every so often you stop and speak sweetly to them, like you do at home even though every instinct wants to shout otherwise....... Or play mellow music on the car radio or stero.