Same as you wagon, baby reverse behind passenger, hi liner in the middle and convertible behind driver. It gives the driver more leg room and the oldest is the only one who can do their own belt plus. The older one next to bubs means baby is less likely to be poked or puled. We also purchased a seat belt extender on eBay and its great, dd can reach to clip her belt in without the clasp being buried between two seats. We have a commodore wagon

ETA we would have liked the independent ones to be on the passenger side but DH can't drive the car if the baby seat is reversed behind the driver side. I tend to get the baby in the carrier first then let the older two out and hold their hand until on the path.