My friend's 2-year old daughter throw up everytime they commute to places, either by taxi or shuttle. Is there any way to avoid this?

My sister used to be like this before. What my dad did was to stock up on candies in his car, so maybe you can do it, too. Bring some candies; mentholated can be even more helpful because of the smell. Also make sure to bring some plastic bags just in case she can't control her barf and throws up.