Dog car seats and restraints are needed for traveling safely, just like you would use when putting small children in your vehicle.
Things to consider: Riding in the back seat, chewing issues, and keeping the dog from falling or flying in the car.
Backseat Safety - Car seats and restraints should always be used in the backseat of your car, especially if you have airbags. If you were to have your dog travel in the front seat and the airbags should release, they can seriously injure or even kill your dog.
No Chewing - Make sure that your dog does not start chewing on her car seats and restraints. Giving her dog chews or dog toys to chew on might help. If they don't, then you may want to pick up a chewing deterrent like Bitter Apple and spray it on.
Stay in Place - One situation where both dog carriers and car seats and restraints are far more preferable than mere indoor car barriers are when you suddenly have to stop short. In dog carriers and car seats and restraints, the dog is "buckled" in, just like you. If you rely solely on indoor car barriers and otherwise let your dog roam free about the backseat, should you stop short, your poor dog could go flying into the indoor car barriers and seriously hurt herself. For obvious reasons when your windows are open you've got another situation favoring carriers or car seats and restraints.
