I can't find the article right now but one of the reasons they get car-sick is because they are frightened and especially if they are in crates and can't see anything. I am a BIG believer of the lookout seats. It has completely stopped any car sickness in any of my dogs. It is a very safe way for them and you to travel. I believe if you use the 1st link to condition them to the car and you purchase a lookout seat you can find them cheaper other places than the link I provided but I wanted you to see all the options and do some short runs with her in the backseat I think this will go away. Usually the 1st time somebody would have a problem but by the 2nd/3rd time no more puking.
http://www.peteducation.com/article....&articleid=794 http://www.snoozer-dog-beds.com/dogcarseats.htm
I LOVE the lookout seats.