We have a GMC Envoy, extra long with 3 rows of seats. Right now we have no kids so sadie has the whole back to herself. The seats are always down and she can stand, walk around, or lay on her dog bed. There are several vents for heat/ ac in the back so she's quite comfortable!

There is also an Envoy XUV that just came out that has some kind of window opening in the back that sounds neat.

As you can tell, if you want an suv or minivan there are lots of options!