I actually went through a similiar thing with my kitties once. We moved from Texas to California by Uhaul. The best thing I can suggest is what we did...as we had three kitties...all three with very different personalities.
My kitty, Keykat, was a VERY laid back, relaxed cat, and she rode outside the carrier, just loose in the cabin of the Uhaul with me. She just slept on the seat, and went down to the passenger floorboard to her litterbox when she needed. We also had food and water out with her when she needed them. Now, this is a rare
thing for a cat to be comfortable with, and I would ONLY suggest trying it after a bit of driving, and ONLY if your kitty didn't panick in the least about being in the car to begin with.
Our other two were as most cats are...and weren't the type that would have handled that well at all. We basically kept them in their carriers up in the cabin with us, and would pull over and let them out of their carriers in the car every couple hours to use the litter box and eat & drink if they needed. Another thought: slip in some food with them every now and then, and slip in a small water dish every half-hour just to be sure they're getting enough water & food.
Yes, you should definitely line the carrier with something in case there's an accident. You could do so with cheap towels, t-shirts, cheap blankets, etc. (something soft and absorbant). Be sure to have plenty on-hand just in case you need to change them out.
Other than that, I would search around online and see what articles you can find.
According to homestore.com,
* Do not feed your pet for at least three hours before leaving on a trip.
* During stops, provide fresh drinking water for your cat. You may also reward it with a snack for being a good traveler.
* If the drive is eight hours or longer, give your cat the opportunity to use a litter pan and offer it fresh drinking water.
* Feed your pet shortly after you arrive at your destination or when you have stopped for the day.
Here's what to put in your pet travel kit: food, water, dishes, can opener (if needed), leash, a few treats, favorite toy and some type of bedding. Don't forget a scooper and plastic bags for cleanup!
There ya go! That's my best advice! Hope it helps!!