We are about to have our third child and I need recommendations on the best way to set up 3 across in our vehicle. We have a 4 door ford lariat. My kids are currently in sunshine kids raidian 80 and a graco turbo booster and the newborn will be in a chicco keyfit 30. My 6 yr old is very tall and closely approaching 80lbs and his buckle Is getting to tight in the radian so he will be transitioning into a graco high back turbo booster and I'm not sure the best position for this seat since we have to buckle it everytime. Not to thrilled about him not being 5 point harnessed any more but not many harness at 80 lbs and up.