I totally hear ya, Sydney is a real puker in the car, every time. I can just jingle my keys and she will start frothing. What you need to do is allow them to willingly get in on their own, this is a big first step and helps then get over the nerves part of it. Then, just sit in the car with it running, next time go down the road and back and slowly make the trip longer and longer. I have managed to be able to get Sydney up to a 15 minute trip with no real frothing and throwing up by just doing this. Just this morning was the first trip we took where she was not crated and we were successful. If we are going on a long trip, she is sedated and crated with a towel over the crate so she doesn't see the movement outside the window.
There is apparently a new medication for car sickness that doesn't knock them out so my vet is going ot get me to try that the next time I need a refill. I will let you know how that goes.
Casie, HATES riding in the car, and vomits or drools uncontrolably every time we think of a car ride. There are meds you can give them for this, if you want a dopey dog. But the vet told me to make sure we don't feed him before we travel...and then make sure he has water for the trip. Crackers will help with the nausea....and then take frequent short trips to get her used to riding in the car....good luck!
At first we didnt have a problem with Chuck in the car. Now, every once in a while he will get sick. I think we figured it out, for him though. As long as he is not in his crate, sitting still in one of our laps with the window open (to let in natural air), he is fine. He loves to put his head out the window and never gets sick when we do that. Once he is put in his crate, or the windows aren't open...he will throw up. We haven't taken him on any long trips (over an hour) but the ones we have taken him on (quite frequently) he does just fine. =)