Have friends with new Odyssey and they haul tandem + single easily.
We own a '97 Honda Accord Wagon and haul custom tandem and single inside with hatch shut and all our gear for 1,000 mile trip.
Luggage that we dont have to get to lies flat on floor. Tandem goes on top of that (with pedals, wheels,capt seatpost/stoker bars removed). Then heavy blanket, then single with pedals/wheels removed.
Have enough room behind passenger seat to stow suitcases we need to get to at motel stops. The rest of our stuff gets then packed in where there's room. And there's room for the 2-of-us up front.
Best gas mileage on this trip was 36.2 mpg, most of it on scenic back roads and some Interstate.
Keeping bikes inside vehicle saves gas, keeps 'em out of the elements and away from possible theft.
Works for us!
Pedal on TWOgether!
Rudy and Kay/zonatandem