Then I doubt they would work either, as they are a 'natural' remedy rather than a medicine. They also vary greatly in price, this site has them on offer:
She is trained to almostgun dog standard but I don't shoot anymore & get loads of exercise even if she does not work and my wife spoils her rotten. It is only when we travel she makes a fuss even though she will jump in the car by herself.
Probably thinks she is going shooting then! Try travelling her in a covered crate so she cannot see out, going short journeys
and gradually increasing the time, even just start by letting her lie in the car and only moving it out of the drive or just up the road. Try giving her a bone or chew while she is in there.