The Ascent has two 3-point seat belts on the rear sofa bed and an inflatable bed on the front cabin. Anyone has experience using these features with the 3rd passenger on a long trip?
3 point belts in the rear are certainly the best you can expect in the rear of a "b" van, and the inflatble front bed will probably be fine for someone up to age 10 (maybe a little older). I've also heard the short Sprinters ride well for rear passengers. But I have no direct experience.