Check out this water bottle - one side for your drink and the other for your dog's water. Comes with collapsible travel cup for your dog too http://www.dfordog.co.uk/h-duo-dog-water-bottle-travel-cup.html
There's nothing worse than when your dog gets ill in the car. However there are some solutions, as this article lays out. If you're worried about how your dog behaves in the car then click through to learn more!