gophoenix,
We have traveled at various times with 3 cats, two were adult at first time out and one about 6 months or so. The first we tried in a carrier in the back seat of a Ford pickup, foamed at the mouth and moaned/waled/cried for the first mile - couldn't stand much of that and let her out, she curled up on a towel on the console and the next 2100 miles were trouble free except for the carrier that was in the way. She probably had 20-25K miles on her frame when cancer ended her touring. The next two we let them pick their own destiny in the class A and after a couple miles they found their places and all was good. We have been told by several vets that cats don't travel well, but our experience is somewhat biased since we have really not seen an unsolvable problem. None have traveled in the PC, we have since found/explored using cat/house sitters and that seems to be working better at this stage of our travels/lives. Gotta admit about a week/10 days out, a frequent topic becomes: wonder what the kitties are doing? Cats are kinda strange little fur people, they seem to like being with their people or just being left at home doesn't seem to really affect them all that much either way. Would not try that with a well integrated family dog though - separation anxiety can really mess their little pea brains up. One thing that I absolutely will not do is kennel any animal unless sick.