We have trouble with some dogs and not with others. Remember that some dogs DO get motion sickness just like we do! (including me barf).
Like the others here mentioned, try and make it a pleasant association, as in relaxed, snacks, fun, happy faces and at first just a trip around the block. It's awful when the dog associates going in the car with "Going to the Vet" but sometimes that can't be helped. Try taking her to happy places that are not far away. She will do well I bet! Best of luck!

Darrolanne from CA