I have to say-Crate, crate, crate! Remember, anything loose in your vehicle, including animals become missiles in accidents. Not only do they have a much greater chance of getting hurt, killed or lost in an accident, but the animal flying through the air can cause damage to you. They are much safer in a sturdy, plastic crate. More than one dog has survived a serious car accident because their crate protected them-think carseat for children. A crate cover is a great idea, if the cat doesn't like to travel. Make sure it covers any "open" area. I would put a puppy pad, or depends type pad in the bottom to absorb any wet accidents, with an old towel over the top for comfort. Also, be aware there is a good chance the cat may pick up fleas in the hotel room. If the cat is not UTD on flea treatment, I'd suggest treating prior to the trip. Lastly, I would NEVER take a cat, my own or any other for a potty walk. I have seen cats practically turn themselves inside out to get out of harnesses. Personally, just not worth the risk for me. My dogs can go for eight hours w/out a potty break, most likely the cat can wait until you get to the hotel.