i suggest getting a dog with the following attributes:
- medium size (easy to pack around him/her) dog.
- MUST be able to jump in/out of vehicle on its own.
-mix breed (smart and not full of health issues)
- outdoor dog vs a lap dog. Leave Feefee at home. Carrying a dog around like a cat in front of your buddies is gay
- non barking breed. This is purely based on training but certain breeds have a shriek bark or a yell that is rather annoying and your fellow campers will hate you for it.
- a smart dog that can be trained and knows proper behavior in and out of the vehicle. Again, this is purely subjective but you can usually pick out the parents that seem to be more on the intelligent side.
- a non aggressive dog - This is purely subjective and based on perception.
-a water dog is great too.
-dogs are an extension of the owner so he should exemplify you in some ways IMO.
Ok, let me tell you about my breeds so that you get an idea of where I'm coming from! I used to have a Rottweiler who was a GREAT dog. He was trained (therapy dog) and loved the outdoors. All the kids in the neighborhood loved him and came over to play with him. He commanded a huge amount of space in the rear cargo area so packing around him was nearly impossible. We wanted to make sure that he had plenty of room to move around in the 15+ hour trips that we often took from the Midwest. As he got older, he developed the usual hip issues and no longer could hop in/out of the vehicle. Finally, he stopped going camping/wheeling with me because he just didn't appreciate being bounced around
When he passed on last year, it was truly the saddest day of my entire life.
Now, picture a Rottweiler coming out of the back of the 80 and you can imagine all sorts of things happening - moms would grab their kids and try to stuff them back inside their vehicles, grown men would pause and wonder if they were going to be eaten alive. He'd always be tied up when there were other folks around that we didn't know, etc, etc. You get the point. Perception is reality, as they say. Breeds like Pitbull, Rottweiler, Doberman, Shepheds, etc seem to make people behave in a different manner.
Then came Riley, Border Collie mix dog and between the two of them, the cargo area was plum full! We took them both camping until the Rotty was not able to. Now that the Rotty is gone and I have the medium size dog, life is actually very nice.
His size is perfect for trail running, camping, packing, wheeling and good for all parties concerned. He is light on his feet and knows how to behave when there are other vehicles around. Everyone loves him and he is not intimidating to anyone. I don't have to worry about him at all. He comes when I whistle for him and the kids who don't know him like him immediately.
The Border Collie mix breed is a blessing for our family. He is smart, likes to herd the little one around is protective of our family. He is easily trainable and is super LOW maintenance. We rescued him in Chicago where he was tied to a tree so we call him our Ghetto dog. He also loves water and is comfortable in all environments. He is a very confident dog and we love him tremendously. He doesn't eat much when we go camping so it's easy to pack for him! He can sleep in a tent or in the back of the 80 or simply on the ground tied to the bumper. He just doesn't care. He is also too smart to play fetch
I'm not pushing any breed, just gave you two examples. I don't mean to offend anyone with my comments!
is safe! They never complaint about the heat, but when it over 100 they will try to find shade in the desert. The love the LC and know it's theirs. In fact, I took out the middle row seats for them. My human kids have left the nest and don't ride with us anymore! 
ff the soapbox:
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