Check this out: we just traveled to the coast in our Sienna with no carrier on top. We put our luggage in the back, took out the 2 captains chairs in the middle, our 2 kids sat in the back bench seat, our full-grown Great Dane rode where the chairs had been, and we were able to take his 48"x54" crate too, dissassembled and split between the back with the luggage and the floor where he was laying. I had planned on buying a carrier, but now I'm not so sure!