As you may remember, Gina did the cross-country drive with all her cats in the car. What she did was, in the time between shen she knew she was going, and when she actually left, she put a few in the car and take them for a short drive - 10 minutes, then a few days later a longer one, 20 mins. etc. - got them acclimated to the car, and accustomed to a car ride being an okay thing that does not necessarily end at the vet's office. It worked for her cats ... maybe they can do this with theirs?

The microchip is important, just in case.