Yes, always travelled with cats and dog.
For those with problems with calming dogs and cats (travel and thunder and vet trips too), try Bach Rescue Remedy (natural essence-remember to dilute it!), and for cats there is cat pheromone sprays (Feliway is a good one) that you spray around and on your clothes (but not on the cat).
One problem I've had is they stand on the door buttons that unlock the doors in some vehicles (I let them out while I'm in a store, usually).
Even the shy ones like going into Petsmarts though.....except they'd have me buy everything in there ...because...well, they think they deserve it all!!
I never travel without my journal. One should always have something sensational to read.