Ginger Snaps didn't work for my Lil Deuce Coupe either. From suggestions here, I give him 1/2 a Bonnie tablet. Its like Dramamine, but doesn't cause drowiness. We're planning a 7 - 8 hour trip in a few weeks, taking all 5 of our babies!
I must admit, I am a little stressed over the thought.
We'll be staying in the RV, which will be fine, its just the traveling I'm dreading.