Mine travel in their sturdi bag which gets buckled into the seat...
www.PetCarrier.com :: SturdiBag Pet Carriers :: SturdiBag™ Extra Large Divided
They each have their own side which I put a blanket and toy in.
I do nothing to prevent anxiety... they are fine in the car.
On long trips, I make sure to stop frequently for pee breaks and water and also to give them a chance to stretch their legs.
This summer we drove 12 hours each way and they were fine.
