
I have had a lot of experience with this, particularly with my latest pup who is now 6 months old.
A word of warning though, what works for one dog, won't necessarily work for another, they are all different.
First of all, I don't advocate not feeding the dog before travel, about 1 hr before travel I feed a few dry biscuits, yes ginger is a good ingredient, but I tend to feed the crystalised form, not in biscuits because of the sugar. Sometimes when a dog has an empty stomach it can just exacerbate the problem.
I also use Bach rescue remedy as it calms them, understandably, they get stressed when they are sick and this often makes the situation worse. I put a few drops of the RR on the nose leather (as recommended by Teri ;) ) not down the throat as it can be to acidic for an upset gut.
There are many homeopathic remedies that you can try, my homeopathic vet makes up preparations for me on a "needs must" basis.
And lastly, if you pup goes in the car on frequent but small journeys this helps greatly.
When we moved 2/3 months ago, we had an 8 hour journey to do, I was not looking forward to it with my then 3 month old pup, but doing what I have suggested above helped her greatly and of course we had lots of stops for her along with plenty of air. She travels in a cage in the estate part of my car covered with a towel.