I am trying to figure out if there is any configuration in which I can keep my oldest son in his clek oobr booster. I am expecting my 3rd child and am trying to choose his infant car seat, I'm leaning towards the britax b safe. My 3 year old is in a frontier 85 currently behind the drivers seat and my 6.5 year old is in the clek oobr. My car has a built in booster and my oldest son is 50lbs and when using the built in the strap falls appropriately on his shoulder. My concern is his safety in the center between the two seats and his ability to get out of the car in the morning during the curbside drop off at school. I'm hoping there is a way I can keep him in the clek behind the passenger seat and put the infant seat in the center. Any suggestions (other than replacing the 2 very expensive/ relatively new seats I currently have) would be greatly appreciated!