I don't know what an ESS is, but I have heard that some dogs have an ear condition that causes them problems when driving in a car. I have mostly heard of this in Border Collies, but it could be the cause of your dog's behavior. That's the only thing I can really think of, unless your dog isn't used to driving in the car.
Our puppy whined quite a bit the first few times she rode in the car, but that was mostly due to her unfamiliarity with cars and she was only 3 months old. She's 6 months now and has no problems with riding in the car.
If you're really concerned about it, I'd recommend contacting your vet. They would know much better what the causes could be and it's better to seek professional advice when it comes to your dog's health.
