Traveling with a cat and ferret.?

I'm going to be traveling 10 hours with my cat and ferret. I've had them both in the car before but never for that long. The cat stays pretty calm for the most part but I'm worried that after a while she is going to get antsy. The ferret usually just constantly tries to dig out of her carrier. What can I give them to calm them down to make it more peaceful? Also, I know that theyll need a potty break but since they both use the litter how am I supposed to go about doing that? Thanks!