My lab is close to 80 pounds, and her yellow fur gets in everywhere, and is tough to get out of carpeting once in.
If I don't much else to carry, I line the cargo area with an old sleeping bag, and try to get it over the backs of the rear seats too.
Failing that, I fold the rears down, and spread out two sleeping bags.
We do have a dog crate, but its huge, (wire mesh and larger than the rear of the jeep).
I never let her come forward, even though she wants too.
After about 20 minutes on the road, she settles down, and goes to sleep.
I usually preface every trip by telling her where we're going in a happy voice,
even if its to the vets. (my bad)