My son is 12 years old. He is roughly the size of an 8 year old and 43 lbs due to growth retardation from his two genetic syndromes. He has been in a Graco Nautilus since 2011. The car seat is coming up on the 6 year expiration so need to replace but he still fits in it without much growing room left. He is getting spinal fusion this summer and that may lengthen his torso height a bit once they straighten his spine. I really need a 5 point harness seat with a taller back. I need a recommendation for a new regular seat but we will also be requesting a special needs car seat soon so I need a recommendation for both kinds. The only thing we need with the special needs one is again 5 point harness more growing room then the Nautilus and swivel bottom option to make transfer from his wheelchair to the car seat easier. The regular one will be in our second vehicle and not used as often. Also I'm not sure how big a deal it is going to be but his orthopedic surgeon said since he is so skinny that his rods they will be fusing to his back will be quite prominent. I don't know if that is going to cause problems or not with seating and positioning. He is my only child so car seats don't need to be narrow since he has the whole back seat to himself.