The main reason for child car sickness is that the kids can't see out, so instead of looking out, they look in and concentrate on hand-held computer games and DVD screens. SUVs with opera style seating where the rear seats are higher than the front seats and front head restraints don’t impede the view forward are best. If you only have one child, by far the safest place to seat it is in the centre of the rear seat where it can see forwards easily and if the car ever crashes will be furthest away from any of the crumple zones. (Before hundreds write in to remind me, an old wives remedy that seems to prevent car sickness is to seat the children on paper.)