I'm trying to work out seating in my Dodge Caravan, with the funky sealt belt geometry. The Vivo and the Compass Folding booster work for my middle son, but my oldest is very close to the top of the belt guides. None of them placed the lap belt well on my youngest DS, but the Parkway works well for him in the 2nd row, (and the other seat is our carpool seat) so I need to get my oldest into that pesky 3rd row. The Harmony folding booster worked for the belt retracting, but was too short. It looks like the Defender is a taller booster. Has anyone used it in booster mode? DS1 is 9YO (next week!), 55lbs, and 53" tall. Torso height is around 18.5". Because of the geometry back there, a backless won't work. The belt sits a couple of inchesin front of him. I also tried the Evenflo Amp, the belt guides were compatible, but it wasn't tall enough either. The parkway is marginal in belt compatibility. I know it is one of the tallest.