We have a 2010 Grand Caravan and I'm in the middle of the great booster search for our back row. I've read SO many conflicting reports of what works back there! I had someone tell me yesterday that they have successfully used a Harmony Dreamtime, Evenflo Big Kid, regular Turbo and Turbo with Safety Surround.
I tried our regular Turbo out there with DS yesterday on the highest setting and it does slide pretty freely and the belt stays in the guide and doesn't twist. DS rides in the center right now but I really want to have a good option for outboard and I'd love to have something a little more substantial than the Turbo. The Monterey I ordered works great in the center and in the captains chairs but isn't great outboard. It has the new gray belt guides and the belt does retract but slower than I would like. It worked better for DD's height setting than for DS's. I bought it intending to use it for her in one of the captains chairs in the fall, but I can't decide if I should keep it.
I wouldn't have a problem spending the money for the Kiddy Cruiserfix if it was the holy grail of boosters for the 3rd row, but it sounds like from what Phineasmama says it's just ok.