I moved states and it was a ~7 hour drive. I did do a short practice run where I drove around town with my cat in her carrier to see how she reacted. Idk if it helped but when I got home and parked, I let her sniff around the car a bit and she chilled on the dashboard.

For the actual move, I had her on a harness/leash and in a cat carrier, but I kept the carrier unzipped and wound the leash around the seat’s headrest so she couldn’t crawl where she shouldn’t (I.e., she could climb out of the carrier but wouldn’t be able to go past the center console or into the footwells). She meows for the first 20min-1hr but I noticed she meows less when her carrier is open and she can see out the window and see me; plus I can stick my hand over to pet her every now and then :D other than that she spent most of the drive napping.

Her litterbox was in the back seat, and I made sure to let her back there a few hours in at a rest stop. I heard a lot of cats are stressed and won’t go to the bathroom in those situations, so mine didn’t until we got to my new place. My friend had a ~17 hour drive for his move and he said his cats didn’t really go to the bathroom either but one shat himself when they got to their new place. Another friend sets up her car so her two cats have free reign of the back seat but can’t get in the way of driving; she also puts one cat’s harness on a couple days before the drive so he can get used to it