I think the wording is more to the effect that those child seats which require "LATCH" support, can only be mounted in the second row (as there is no latch anchor points for 3rd row). For kids who sit in booster seats, back there should be fine as the seat raises them to correct level for the seat belt to secure them. I currently use a booster for over 40 lbs and under 5 ft...

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SOLD - 08 X5 (Titanium Silver w/Black Nevada with all options).