I moved 800 miles with Seine- the whole trip took about 16 hours driving straight through. I knew she hated cars so I asked the vet for a sedative, but actually this was worse! She did not fall asleep altogether, she was just very drowsy and upset. She actually did better once it wore off. She was not happy but she was ok.

What worked for her was a small dog crate with a little litter pan, water and towel for a bed. I offered her food when we stopped. She had enough room to lie down and she could use the litter if needed. Also, if it's hot make sure the air conditioning can reach the cats if they are in the back seat.

Best of luck to Alexa, and to the kitties!!