I used to suffer from any motion sickness so badly. I tried all those different travel sickness tablets and none worked. I have also tried those wristband that you can purchase from a chemist but that didn't work either. The only thing that works for me is Phergan. I also find that if I do the driving I don't get sick at all. Sitting in the front rather than the back seat can also help a lot. Never read anything in the car as this makes it even worse. Sucking on some lollies can sometimes help also.
I am the sore of person that gets travel sick just looking at the vehicle I am going to travel in. Not really the best thing when you travel a lot. However, I found taking an antihistamine the night before and the morn of travelling and taking stemitil during the journey completely fixes my travel sickness issues.
Ginger is supposed to be good for motion sickness. In a car must have windows' down in front (no aircon in car!) for breezes to blow. If passenger prefer to sit in the front. Can't read a map in the car, have to stop!
My son used to get travel sickness from a young age, then the doctor suggested phenergan in a liquid form obviously as he was young at the time,but you can also get them in tablet form for adults as well in different strengths.