I have a reptibator in storage that I guess I could pull out for the trip and plug it into an inverter, or invest in the car warmer/cooler unit. What I'm concerned about is the bumps and vibrations. Rolling eggs are not good, but can an egg withstand 12 hours of car vibrations?[/QUOTE]
I'm thinking if they are in vermiculite or perlite, or a substrate of that kind, they would probably be fine. I doubt the vibrations would be enough to harm them.