So a couple weekends ago, my dad and I drove from CT (where I live) to Michigan... with two cats in the car. It was, to say in the least, interesting. Before we left, my dad had gone to see the vet to see whether we should sedate the cats. The vet told us, "Oh, don't worry, they'll calm down after 45 minutes or so, o hohohohoho!" (Okay, he didnt say that last part, but I felt it necissary. If you get the reference... you get cookies.) So we let the cats loose in the car (a 1987 Volvo wagon [standard].
Well, they didn't calm down... for three hours. It was rather nerve wracking, I dont mind telling you, having two cats mewing as loud as they can in your ear, only taking breaks to piss and crap on the seats. (It wasnt so bad, my dad had the foresight to lay down the back seat and put an old rug down.) But eventually, (EVENTUALLY) they calmed down. When we stopped for the night (after six hours of driving) we chose a motel. We decided not to bother the staff by asking whether we could have the cats or not. We just brought them in. 
The next day was another 6 hours of driving. But by then they were used to it. Well, it was fun. That's my story. It's random. WOOT!