Problems with 2008 Toyota Highlander CHILD SEAT

I have a sunshine kids radian 80sl. model us18500. serial 090900106 03565. my latch strap does not remain tight. i can loosen it with one finger, which means my daughter climbing in and out can bump it and loosen it. it also has loosened over time on it's on. when i first install it, it is a completely rock solid install, but if you pull back and forth on the seat a few times you can feel it loosening. i do not feel like my daughter is safe in this seat in a crash. (related vehicle information: model year=2008, make=toyota, model=highlander). *tr

During a recent road trip visiting family, my son was riding in the third row seat in our toyota highlander. shortly before arriving at his grandparents, he told me that he had become twisted in his seatbelt. as we were within 10 minutes of our destination, i told him that i would handle the situation when we arrived. a few minutes later he said that the belt was getting tighter and i asked him if i needed to stop and he said that would be a good idea. before i could get stopped (less that a block), he indicated that he was having trouble breathing. when i looked back, i was startled to find that the seat belt had become wrapped around his neck and had ratcheted back in, pinning his neck back against the side of the car. even after stopping, i was unable to pulled the seat belt out to get it out from around my son's neck -- he was strangling in front of my eyes. fortunately, i was in a city with residents close by, one of which heard me screaming and running door to door, who brought out ...