The rear 3rd only has two anchor points, one on each side so you wouldn’t be able to to do two car seats on the one side (60). And fold down the the smaller seat (40). I think that’s what you’re asking right? Other than that the expedition is a great family hauler, get a max so that you don’t have to worry about putting a seat down
He could use the seatbelt for 3rd row center. Typically, the lower latch anchors may only be used with children less than 40 lbs.
Stephen,
There is plenty of room for 3 across in the 2nd row. The only consideration for the 2nd row is one of the outer seats should have either no car seat or one that uses the lower latch anchors. This allows the tip and slide to function giving access to the 3rd row. Im guessing a rear facing car seat would also limit the tip and slide functionality.
The 3rd row has a couple of concerns:
1. It is more narrow, so you would want to look at narrower seats or boosters. Diono radian and maxi-cosi rodifix both come to mind.
2. the outer headrest are not easily removable. It is possible to remove them, but it takes some work.
The best advice is to bring your car seats to the dealership and do a test fit.
My current setup is 3 across second row with the maxi-cosi rodifix in the middle and 2 Britax marathons in the outer positions. Sometimes when using the tip and slide, I have to nudge the shoulder bolster of the maxi-cosi to allow the outer seat to slide forward.