You might want to add a few drops of Bach Rescue Remedy without alcohol to your babys drinking water. He should drink a little before traveling and you can continue giving him the same during the trip. RR will help keep him calm and less stressed during the trip. My baby likes to travel in his sherpa traveling bag. He feels safe and secure in there so we always strap it into the back seat so he can enter and exit at his leisure. You may also wish to have a little food available. I give mine Ziwi-peak nibbles. They are just small enough for him to easily eat, yet large enough for me to hand feed. He usually eats 6-8 pieces. this helps keep his blood sugar levels even but does not allow for a full stomach something you most definitely want to avoid so he does not get sick and vomit in the car. We are a traveling family...3 days a week...500 miles
I think my boy thought he joined a band of gypsies when we first got him but now he just takes it in stride and is the first to the door when the bags are packed.
Good luck and remember to stop and smell the fresh grass along the way...ours LOVES all the exciting smells. And remember to pack a few of his favorite toys too.