I bought this before season due to plans of some decent travel for hunting this year. I have found it to be extremely convenient. It has traveled behind the seat of car as well as the back of the Tahoe or truck and it stays upright very well so its pretty much mess free. I usually set it out when I get the dog out....let him have a drink if he wants.....leave it down and he can get his fill when we return to the truck. It holds 2.5 gallons of water.
I couldn't find any direct link to the product so here is one for GunDog Supply and Lion Country both.
http://www.gundogsupply.com/drinking-spot.html
http://www.lcsupply.com/Product/Kennel- ... -Spot.html