We have a 2007 R56 and our oldest child is 44 lbs. The Sunshine Kids Radian 80 carseat recommends using the shoulder belt instead of latch once the child is 48 lbs. It also says to keep using the top tether strap in use unless the particular car's specification for the anchor states the weight capacity has been exceeded. Unfortunately, the manual does not say what that capacity is. Does anyone know? We are going to attempt to contact the dealer as well, but not sure if they have the info.