Kipper was travel sick when he was a pup. We built up the journeys slowly and took lots of breaks, but I think age has something to do with it, in that they’re more sensitive when they’re younger. Advice is often get them forward facing in the central line of the car (I guess minimizes rocking?) and give them fresh air but this didn’t seem to make a huge difference with Kipper.
I wonder if treats with ginger in might help?
We had the same with Barley when she was young and did much the same as Her Majesty, Queen of Turnips. Eventually Barley was fine, loved the car and quite often was reluctant to get out, particularly after camping trips!