I need to be able to fit a LBB in my car for carpool once a week. I currently have a Marathon Clicktight and a Recaro Performance Sport installed in the outboard positions. I bought a Harmony booster but it will not fit between the two other seats. Do the car seats need to be absolutely centered on the car's seat when installed, or can I shift them closer to the doors as long as I can still get a tight install? I definitely have room to move the Marathon closer to the door, but I don't know if that is acceptable.

My other option is to move the Marathon to the center position but that's not my preference (my kids do NOT need to be within arms reach of one another right now).

Any other ideas?