We want to take our five year old, 46", 50 lb child to Yellowstone this summer with a tour company that is "family friendly", but uses the standard 15 passenger vans - either a Ford P350 E series XLT or a Chevy Express, 09-10 model years. They said the Frontier "would fit". However, they don't think there is anything in the rear of either vehicle to use as a tether and also they remove the furthest rear row of seats to enlarge the back cargo area anyway. They do have shoulder belts for "most of the seats" in the van. We have lots of travel experience and have no problem lugging the seat around. We wonder if we should just rent our own vehicle if the Frontier cannot be tethered in theirs. Any thoughts? We really don't want to drive if we don't have to.... but safety comes first.