sorry this is probably asked a lot.
I remember reading a post a long time ago that had some really good points about which side to put the older kid that was easiest to get them both in/out of the car. I can't find it.
I'm trying to think logically about which one you put in first etc. and I'm coming up with nothing, lol.
Re: where did you put kids in backseat? I know this was asked...
I have the baby behind me, the oldest behind the passenger seat.
Before DS could walk up/down stairs well while holding my hand, I would put DD on the top step while I carried DS to the car/strapped him in. Now I hold DD's carseat with one hand and DSs hand with the other and walk them both out at the same time.
We're putting the baby behind the driver and Cole behind the passenger. We have on-street parking, and Cole is a runner - I do not want him a - walking in the street at all, b - not able to hold his hand at all times. This way, I can put the infant carrier on the sidewalk and not the street, and strap in Cole. Then place the infant carrier in the car behind me, and get in. Getting out, use both hands to get the infant carrier out, then either assemble the stroller and put Owen in, or carry Owen over to the sidewalk and let Cole out.
This way, no running away, no Cole in the street, and minimal fights
We have the baby behind the passenger and DS behind the driver. When we go out to the car, I carry them both - and when DD was a baby and lighter, I would have her in the carrier in my left hand, and then be able to lift her into the car with one hand and click her in, all while holding DS on the right. Then I would put DS in behind the driver and go.
If your oldest is already forward facing, he should go in the middle if possible. Rear-facing children are more protected than forward-facing children for the simple fact that rear-facing is the safer way to ride, even if they're an infant. Both of my boys are rear-facing and outboard but when I turn DS1 forward facing, he will go in the middle next to DS2 who will still be outboard.
This is all from a safety standpoint though, which trumps convenience in my book when it comes to the car.