Maybe you could get some car sickness bands from the chemist, they have "studs" that sit on your pressure points on your wrist, I have some & they work for me.

I second the Bundaberg ginger ale

Watercrackers to nibble on on the way

When I was a kid I used to get really car sick when I was reading & was told to look out the windows. Apparently people who are sitting in the front are less likely to get car sick because the are looking where they are going