Start preparing your cat early for the trip - take him for some car rides where nothing bad happens, like seeing the vet.

Many cats will not use a litter box "out in the open" - believe me, we tried. My cats have ridden in the car cross country, New England to Florida, and generally all over with us. Not once did they take advantage of the "mobile facilities" we offered, even when we place it in the trailer. However, once we hit the motel, well, you don't want the details. (where's the smiley for "holding one's nose"?)

I would suggest breaking the trip, taking two days instead of one very long one, because Kitty may not drink, eat or relieve himself at all while actually traveling. Did you know La Quinta Inns are pet friendly, and have no pet fee?

Important safety tip for cats: if you cat gets overheated while traveling - you were only in that cafe 5 minutes, right? - have one person hold the cat upside down (paws up), stretched out, and the other person pour cool, not ice cold, water over the cat's belly and rub the water into the fur until the cat is cooled off. We got that one from our vet during what fortunately turned out to be only a minor crisis. It worked.

Think twice about drugging Kitty, and if you do, give a test dose a few days before you leave to make sure Kitty doesn't have an adverse reaction, like vomiting.