water dishes in cars don't tend to work too well, you will end up loosing most to all of the water on the drive. I like to use just a wet paper towel in a water dish, it'll hold in the moisture and won't splash everywhere. Also for a longer trip 2 hours. I take a clean margerine tub and cut a hole in the center of the lid. My gecko figured it out soon enough, and with the lip all around the top, no water will splash out. also if you use this idea, keep your little buddies in the front seat with you, so you can keep an eye on them, wouldn't want them falling in and getting stuck now!
Kev