I’ve traveled with my dog in a fully-loaded Sprinter van, in a ‘77 Westfalia bus, in a tiny Fiat 500, in a converted 4Runner, and under the belly of a transatlantic flight to Europe. I’ve done it solo, with one dog, with four dogs, with a partner and her 90-pound shepherd crammed into a tiny space. People ask me all the time which setup is best. And really, it depends on you. But after a decade of trying nearly every version, I’ve got a few things to say.