But if they are in car seats not on the actual back seat it shouldn't really be an issue should it? Or is it a suspension thing?
Its hard to explain but the way car seats seem to be designed, they need the slight recline of a regular rear car seat for them to be in the correct position. Because the crewman seats are straight, the car seats sit at a different, more upright angle and as soon as the little ones fall asleep their heads flop forward.