We had the same problem!
For over two years, Rach (pronounced Rock) got severely car sick beginning from the moment he came to live with us at 14 weeks.
We tried everything, just as I suspect you did!
One day I decided I was getting him over this. It was no way for an awesome dog to live!
So I stopped all car travel and created a plan, an extensive plan. This book shares exactly how we got Rach over his car sickness.
Our plan takes patience, perseverance and dedication. But believe me, once you try it, you will be so glad that you did. Your dog will thank you!