Our two Shelties got car sick and we didn't know what would happen when we started traveling full time in a motor home.
We started spending evenings and nights in it. We told the dogs that we were going to the little house. After a few days they would run to the door all excited to go when we told them "going to the little house". Then after we got everything out of the house and into storage we lived in the motor home for a month while we did repairs, painted and so forth.
When we started the engine and pulled away they were a little surprised but neither one got car sick and they adapted well to life on the road.
They really loved the attention they got when we walked them on their leashes in RV parks.